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#1
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Computer popped
My nephew said his computer popped he smelled smoke. I took it
upstairs and opened it up and unplugged the mobo and hard drives and powered it up and nothing happened. I wish I had thought to check and see if the mobo light was on, but I didn't. I pulled out the power supply and checked the connections with a tester and everything seemed to be working. I took some compressed air and blew all the dust out. I put the powered supply back in and connected it all back up. It worked! Dust? Really? I think that may have been the actual problem. |
#2
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Computer popped
Metspitzer wrote:
My nephew said his computer popped he smelled smoke. I took it upstairs and opened it up and unplugged the mobo and hard drives and powered it up and nothing happened. I wish I had thought to check and see if the mobo light was on, but I didn't. I pulled out the power supply and checked the connections with a tester and everything seemed to be working. I took some compressed air and blew all the dust out. I put the powered supply back in and connected it all back up. It worked! Dust? Really? I think that may have been the actual problem. A capacitor blew. There might be nothing left to see of the capacitor as it blew up. If you knew where to look, you might all of a couple wire stubs, very short, sticking out of solder joints. There might be some black residue there but not always. If it is an old motherboard, some of them were manufactured with defective capacitors. It was espionage gone bad in stealing only half of the formula. http://en.wikipedia.org/wiki/Bad_capacitors Even if it wasn't one of those bad formula caps on an old mobo, parts do fail. If the kid said he heard a pop and then smelled something like an electrical burn then something did fail inside the case. Could be a cap on the mobo. Could be a cap inside the PSU. Dust shorts under high voltage, like inside TVs. The voltage is too low inside a computer. Even then when a dust bridge fries, the smell is of something stale, not electrical or plastic. If you've ever had a space heater sitting around for awhile to gather dust and then turn it on, it's the same stale smell of burnt dust. It's similar to when dust on the fins of baseboard radiators get hot. That's not the same as the plastiky smell of a blown cap. It might work after the cap blows. Depends on what the cap was for. If it was for voltage regulation to the CPU (look at the caps around the CPU location) then there is loss of regulation which means the CPU might be receiving the wrong voltage or too much ripple in it. If it were inside the PSU, an output voltage may not be correct anymore. Testers and meters look at average voltage, not at ripple. After reading the above article, look again very carefully at the motherboard, especially around the CPU where there is often a band or row of regulation caps. Read the article on how to determine if you have bad caps. Look for any scorch marks on the mobo but they may be small or not present. I've seen caps blow where there is nothing behind to identify there was a cap that exploded other than a couple tiny stubs of wire used to wave solder the cap to the PCB (think of a person hold 10 sticks of dynamite and after the explosion all you see are the soles of their shoes). If you can't find where the blown cap is now missing from the mobo, the next best candidate is inside the PSU. No, it wasn't dust as you hoped - unless your nephew has a CRT monitor but you didn't mention that. |
#3
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Computer popped
Metspitzer wrote:
My nephew said his computer popped he smelled smoke. I took it upstairs and opened it up and unplugged the mobo and hard drives and powered it up and nothing happened. I wish I had thought to check and see if the mobo light was on, but I didn't. I pulled out the power supply and checked the connections with a tester and everything seemed to be working. I took some compressed air and blew all the dust out. I put the powered supply back in and connected it all back up. It worked! Dust? Really? I think that may have been the actual problem. I wouldn't reuse a power supply that had done that. There's got to be a reason for that noise. Dust is not the problem. It would take a seriously dirty install location (computer next to deep fat fryer in restaurant) to get enough greasy/salty mixture, to cause the main cap to arc over. ATX supplies are good, but they're not conformal coated for extreme conditions. But they should be able to handle a dry dust OK. Excessive dust or hair ball, will cause things to overheat. But arc-over requires something to go with the dust, such as high moisture, or grease/salt. For example, microwave popcorn exhaust is excellent for ruining AC powered circuits. Nice mixture of grease/salt/water to go with any dust present. ******* In fact, I wouldn't have reassembled with that supply and tried powering it again. The thing is, it could "pop again", and if some protection circuit inside had failed, damage some computer hardware. I have a load tester (and not the crappy kind you can find at retail for $20 either), and I'd connect the supply to that. It's a simple circuit consisting of a set of power resistors, an ATX main wire harness, and it puts a load on a power supply. Mine is not set up to draw hundreds of watts, and is not intended as a stress tester. It's more of a circuit I can use to simulate an idle computer loading. Then, I run for two hours or more, and check the output voltages with a multimeter. A bat-handle switch between PS_ON# and COM, is used to turn the supply on and off when desired. An 80mm fan blows over the resistors to remove some of the heat. I have a supply here, that is perfectly functional. I could power a computer with it. It passes the "visual inspection test". It passes my two hour load box test (meter shows voltages are OK). And yet I don't use it inside a computer, and it's not in my "pool of spare parts". The problem with that one is, it injects noise into the AC line at a phenomenal rate. I checked inside, and it has the usual filter network on input. And it creates so much noise, it causes my ADSL modem to lose sync, over and over again. My ADSL modem hasn't lost sync since that ATX supply was removed from the computer room. Any time a supply misbehaves here, I change it out. ******* The power supply may have a warranty. Check the date of purchase. If you remove the top plate on the power supply, one of the screwed can be covered with a "warranty invalid if screws removed" sticker. The sticker is so they can tell you've tampered with it. If the warranty has expired, you can inspect it. What you want to do, is a visual inspection of the inside. It could be, that there is a leaking capacitor inside. You'd be looking for the "brown-orange rusty stuff". If the domes on the cylinders with the plastic sleeves (capacitors) are cracked, the electrolyte will come out. And the rusty looking material is the result. One of my Antecs (Channelwell) failed this way. If it looks like this, it's cooked and headed to the landfill. Yes, some hobbyists repair them, but you need access to a good supply of replacement caps, to contemplate fixing a failure of that nature. http://upload.wikimedia.org/wikipedi...4/PSU_Caps.jpg ******* To select a replacement supply, go to Newegg, list all the ATX supplies, then "sort by rating", to get the best ones at the top of the list. Scroll down, until you find the best price and rating compromise. For example, I found a Sparkle brand supply that was a pretty good balance, and saved me a few bucks. The Sparkle was bought, based on the Newegg rating, but was purchased from a Canadian supplier carrying the same model. Two of the other supplies I got, were clearance items at a local computer store, and now I'm sorry I didn't buy more of them (Enermax, last generation stuff). When you read the reviews on Newegg, take note of the DOA rate, as it's an indicator of stuff to stay away from. And no $20 supply, is worth buying. It is going to cost more than that. Try around $50 or so. Paul |
#4
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Computer popped
On Fri, 22 Jun 2012 23:26:16 -0400, Metspitzer
wrote: My nephew said his computer popped he smelled smoke. I took it upstairs and opened it up and unplugged the mobo and hard drives and powered it up and nothing happened. I wish I had thought to check and see if the mobo light was on, but I didn't. I pulled out the power supply and checked the connections with a tester and everything seemed to be working. I took some compressed air and blew all the dust out. I put the powered supply back in and connected it all back up. It worked! Dust? Really? I think that may have been the actual problem. I took the machine back down stairs and hooked it up. It didn't work. The location is in the center of a very large room. There only outlets are along the wall. The computer was plugged into a power strip and then a 25 ft drop cord. The drop cord may be 12 Gauge, but I am sure it is at least 14 Gauge. I measured the voltage and it was 119. I brought the machine back upstairs and it works again. The power supply is still under warranty. The mother board is not. Since both are working now, I have no idea which is bad. I did look at the mobo for signs of smoke, but didn't find anything. My nephew has better eyes than I have, but has less interest in finding the problem. He didn't find any signs of smoke either. The power supply came from NewEgg. How can I know which failed? I think what I am going to do is take it back down stairs. If it works, I will leave it and if it doesn't I am going to send the power supply back. Like you guys have said, the pop is pretty good sign that a cap died. The mobo doesn't look like it has a bad cap, that gives the PS more weight as the problem. |
#5
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Computer popped
Metspitzer wrote:
I took the machine back down stairs and hooked it up. It didn't work. The location is in the center of a very large room. There only outlets are along the wall. The computer was plugged into a power strip and then a 25 ft drop cord. The drop cord may be 12 Gauge, but I am sure it is at least 14 Gauge. I measured the voltage and it was 119. You measured the voltage where? At the power strip into which you plugged the computer? If so, are you using the same power cord to the computer downstairs that you use upstairs? When you plug the computer's power cord (just that) into the power strip, do you see normal voltage at the end of the computer power cord? How did you measure voltage? With a meter? How about an outlet tester (to make sure the wall outlets are wired correctly)? Is it a grounded outlet? If so, did you test the ground is grounded, like checking continuity to a water pipe? Can you plug a working lamp into the same wall outlet and again into the power strip to make sure the circuit can handle a load? How about a vacuum cleaner? Just because you measure voltage doesn't mean the circuit can handle the current load. I've seen fuses that blew. Normally the metal strip blows apart; however, in one case, there was just a crack in the metal strip and they were touching. So voltage measure fine until I put a load on that circuit whereupon voltage dropped to zero or very low. I could get some things to work, like an LCD clock but a radio or lamp would fail. Check the fuse for that circuit in the downstairs room. If you have breakers, flip the room's breaker twice (off-on-off-on). Does your electrical box have a whole-house surge protector? How about the power strip? Get rid of any surge protectors if possible and use unprotected wiring to power the computer. Surge protectors that use MOVs work by shorting when there is excessive spike voltage. This breaks down the MOV over time. Eventually the MOV fails first by shorting and then burning open (and why MOVs can cause fires in surge protectors if the short isn't quick to blow open). Get rid of the surge protected power strip and use an unprotected one for now. Surge protectors have been determined to cause some house fires. I had a video link at one time that showed what happens to too many so-called [cheapie] surge protectors that are continuously spiked to break down the MOV (in a short time instead of the long time normally experienced by a MOV in shorting the spikes) and the power strip burning up. It was dramatic and scary. See http://www.youtube.com/watch?v=uCqK_2q_Mhg at its 0:50 timemark and again at the 3:00 timemark (the MOV has already been shorting catastrophically for awhile and getting host before you see a fire like what is shown). Most "fires" are internal to the surge protector's case so you might only see some scorching or carbon smudges. Some protectors use fire retardant encased MOVs because of how they catastrophically fail after an excessive number of spikes getting shorted through them. Their description of a MOV as a "sponge" to absorb the spike is wrong. It *shorts* across the pads of the MOV to short the spike to ground although some surge protectors also have MOVs across the hot and neutral to handle those spikes. A coil will absorb and nullify. A MOV shorts. The vast majority of consumer-grade surge protectors are surge arrestors in that they short the spike. Some (more expensive surge *suppressors*) absorb the spike and then span the overage over a longer time. One example of a surge suppressor can be read about at zerosurge.com under their tech info section. A MOV is a ceramic wafer with a metallic scintered screen inside that reduces impedance on a spike (which looks like high frequency). The spike punches (burns) through the screen from one side to the other. There is NO absorbing of the spike. It gets shorted across the MOV. This shorting burns a path through the MOV so it degrades over time. Eventually it cannot handle a spike and can short for too long before completely opening. The high current during the extended short causes fires. Hopefully if you have a protector using old MOV technology that it also is fused to cut out when the MOV catastrophically shorts to prevent the high current that generates heat and a fire. Alas, again, cheapies using MOVs aren't fused (fuselink or circuit breaker). Some of the better ones put a lamp across the MOV. If the MOV is open (its normal condition) then the lamp is on. If the MOV is shorted, the lamp is off (because there's no voltage across a short). Alas, the lamp being on showing the MOV is open could also mean it has catastrophically failed, shorted and burned into an open condition, and the lamp will be on. The only way to know for sure the MOV is working is by testing it but testing is destructive in that you're shorting and burning out small pieces of the scintered metal within, so don't test too often. Here's some aftermath pictures and videos of cheapie protectors going ablaze: http://www.google.com/search?tbm=isc...protector+fire http://www.youtube.com/watch?v=Q5DieEF0_vw http://www.youtube.com/watch?v=1VZbNmbf2vY http://www.youtube.com/watch?v=arN-rGcejNw (*) (*) This guy really isn't demonstrating spiked voltage that these protectors are supposed to short or absorb; however, remember that the protector is getting zapped many times over its lifetime (before catastrophic failure). Whether the protector gets hot enough to cause a fire or itself burst into flames depends on what components were use inside, insulation, fire retardants, and type of enclosure (the plastic housing could be flammable but then a metallic housing would get hot and catch something on fire against which it pressed, like the carpet, wood desk, etc). If you're going to go cheap on a surge protector/suppressor then don't bother buying one and just get a power strip. Either pay for good protection or don't pay at all. You think it has 14-guage wire in the power strip's cord. Does it really? Did you buy an $80+ surge protector or an under $30 cheapie? The cheapies are often nothing more than an extension cord and that is 18 guage (i.e., lamp cord). Although some sites say 18-guage is okay for a 16A load and 16-guage okay for 22A, I still find cords getting warm enough to detect with my hand that are under these max loads. If the cord feels warm then the cord's wire is undersized. The load ratings are for a free standing wire (in air and by itself), not when you bundle them inside a vinyl case with other wires, run along the carpeting, or shove together with other power wiring behind your desk or entertainment center. Another term for chassis wiring for amperage rating is the free-air amperage rating. Once you bundle the wire with others, the max current rating goes down to about 60%, or less. So your 14-gauge single-wire free-air rating of 32A goes down to 17A when bundled; see http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity. How about the extension cord you used between the wall outlet to the surge protector? Most cheap extension cords are just 18 guage and they'll get warm or hot if you use all their outlets for big power devices connected to it. Plus using an extension cord with a surge protector is ALWAYS a no-no. Get a surge protector with a longer cord. 10 feet of power cord can induce a 400V spike during a surge, and then add the length of cord for the power strip. Also, for surge protection, make sure you use the same wall outlet for all protected devices. Don't run a surge protector from one wall outlet to your computer, another surge protector from a different wall outlet to your stereo, and then connect your stereo to your computer. The length of interior wiring between the wall outlets plus the lengths of cords to the surge protector provide an impedence to a voltage spike that can induce high voltage. How many other devices did you have plugged into the same wall outlet that were drawing power? You might only have a 15A circuit for the room. Current load and wire heating is based on the interior wiring to the wall outlets and the fused load for that circuit, not to a bunch of extension cords plugged into the wall outlets. Did you feel if the extension cord was warm? How many into the power strip? Did you feel its cord's temperature to see if it was warm? Did you check the power strip's cord end, each end of the extension cord (just get rid of that to be safe), and the wall outlet for scorch or carbon marks from arcing? Making you have crappy connections. Look at the prongs on the cord ends to make sure they aren't oxidized, corroded, or pitted. You'll need a flashlight to look into the female cord ends and into the wall outlet. Arcing will deteriorate the connection, up the resistance, and the arcing itself makes noise (and blue arcs if it's dark enough in the room). Since you say the computer sits in the middle of the room, were are the power cords routed? Under foot? If so, the constant stepping on them can damage the insulation or connectors and cause shorts. If you cannot route them overhead in a suspended ceiling, through the walls, or under a raised floor then get a cord protector. You slide the cords into the protector which is hard rubber that won't crush underfoot. Use a strong one (http://www.discountramps.com/hdImage...otector-10.jpg) that is heavy-duty and doesn't crush under the weight of you standing on it with both feet. The lightweight soft vinyl cheapies (http://ak.buy.com/PI/0/500/205675672.jpg) are just for show to tidy up a room's look and do nothing to prevent damage to walked-on power cords since the protector crushes to then crush the cords within. Of course, this means you'll be tripping over the sturdy cord protector if it's in an well travelled area and why some are bright yellow so you don't forget it's there. Check for any frays (scrapped off insulation) on the cords? Got mice in the house? They chew on wiring insulation inside the walls. Squirrels, too. If you have GFI outlets, did you check if they popped? Like you guys have said, the pop is pretty good sign that a cap died. The mobo doesn't look like it has a bad cap, that gives the PS more weight as the problem. Since you say it works upstairs and not downstairs, I'm now thinking you have a bad surge protector, damaged cords, blown GFI outlet, slightly shorting near-blown fuse, or some wiring problem downstairs. |
#6
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Computer popped
On Jun 30, 10:26 pm, Metspitzer wrote:
On Fri, 22 Jun 2012 23:26:16 -0400, Metspitzer wrote: My nephew said his computer popped he smelled smoke. I took it upstairs and opened it up and unplugged the mobo and hard drives and powered it up and nothing happened. I wish I had thought to check and see if the mobo light was on, but I didn't. I pulled out the power supply and checked the connections with a tester and everything seemed to be working. I took some compressed air and blew all the dust out. I put the powered supply back in and connected it all back up. It worked! Dust? Really? I think that may have been the actual problem. I took the machine back down stairs and hooked it up. It didn't work. The location is in the center of a very large room. There only outlets are along the wall. The computer was plugged into a power strip and then a 25 ft drop cord. The drop cord may be 12 Gauge, but I am sure it is at least 14 Gauge. I measured the voltage and it was 119. I brought the machine back upstairs and it works again. The power supply is still under warranty. The mother board is not. Since both are working now, I have no idea which is bad. I did look at the mobo for signs of smoke, but didn't find anything. My nephew has better eyes than I have, but has less interest in finding the problem. He didn't find any signs of smoke either. The power supply came from NewEgg. How can I know which failed? I think what I am going to do is take it back down stairs. If it works, I will leave it and if it doesn't I am going to send the power supply back. Like you guys have said, the pop is pretty good sign that a cap died. The mobo doesn't look like it has a bad cap, that gives the PS more weight as the problem. I've replaced PS units to fix computers. More or less, in determining my problem was I was actually feeding the MB power supplies, predominately, replacing them over time as they failed;- there were, as well, other issues I won't get into. The most single interesting thing to note about all this is current draw. My electrical bills dropped by an amount I'd be ashamed to publicly mention;- I do, rather I should say, have a couple meters and the ability for determining what an electrical device is averaging for prolonged electrical costs. Smoking power supplies, towards the end, yes, even that, too. It was unacceptably a state disproportionately out of hand when I heartily ****-canned that errant motherboard. . . .Just a passing mention, aside from fixing known recidivist computers, in case you notice an escalating whiff of unjustified power bills. |
#7
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Computer popped
On Sun, 1 Jul 2012 04:09:00 -0500, VanguardLH wrote:
Metspitzer wrote: I took the machine back down stairs and hooked it up. It didn't work. The location is in the center of a very large room. There only outlets are along the wall. The computer was plugged into a power strip and then a 25 ft drop cord. The drop cord may be 12 Gauge, but I am sure it is at least 14 Gauge. I measured the voltage and it was 119. You measured the voltage where? At the power strip into which you plugged the computer? If so, are you using the same power cord to the computer downstairs that you use upstairs? When you plug the computer's power cord (just that) into the power strip, do you see normal voltage at the end of the computer power cord? How did you measure voltage? With a meter? How about an outlet tester (to make sure the wall outlets are wired correctly)? Is it a grounded outlet? If so, did you test the ground is grounded, like checking continuity to a water pipe? Can you plug a working lamp into the same wall outlet and again into the power strip to make sure the circuit can handle a load? How about a vacuum cleaner? Just because you measure voltage doesn't mean the circuit can handle the current load. I've seen fuses that blew. Normally the metal strip blows apart; however, in one case, there was just a crack in the metal strip and they were touching. So voltage measure fine until I put a load on that circuit whereupon voltage dropped to zero or very low. I could get some things to work, like an LCD clock but a radio or lamp would fail. Check the fuse for that circuit in the downstairs room. If you have breakers, flip the room's breaker twice (off-on-off-on). Does your electrical box have a whole-house surge protector? How about the power strip? Get rid of any surge protectors if possible and use unprotected wiring to power the computer. Surge protectors that use MOVs work by shorting when there is excessive spike voltage. This breaks down the MOV over time. Eventually the MOV fails first by shorting and then burning open (and why MOVs can cause fires in surge protectors if the short isn't quick to blow open). Get rid of the surge protected power strip and use an unprotected one for now. Surge protectors have been determined to cause some house fires. I had a video link at one time that showed what happens to too many so-called [cheapie] surge protectors that are continuously spiked to break down the MOV (in a short time instead of the long time normally experienced by a MOV in shorting the spikes) and the power strip burning up. It was dramatic and scary. See http://www.youtube.com/watch?v=uCqK_2q_Mhg at its 0:50 timemark and again at the 3:00 timemark (the MOV has already been shorting catastrophically for awhile and getting host before you see a fire like what is shown). Most "fires" are internal to the surge protector's case so you might only see some scorching or carbon smudges. Some protectors use fire retardant encased MOVs because of how they catastrophically fail after an excessive number of spikes getting shorted through them. Their description of a MOV as a "sponge" to absorb the spike is wrong. It *shorts* across the pads of the MOV to short the spike to ground although some surge protectors also have MOVs across the hot and neutral to handle those spikes. A coil will absorb and nullify. A MOV shorts. The vast majority of consumer-grade surge protectors are surge arrestors in that they short the spike. Some (more expensive surge *suppressors*) absorb the spike and then span the overage over a longer time. One example of a surge suppressor can be read about at zerosurge.com under their tech info section. A MOV is a ceramic wafer with a metallic scintered screen inside that reduces impedance on a spike (which looks like high frequency). The spike punches (burns) through the screen from one side to the other. There is NO absorbing of the spike. It gets shorted across the MOV. This shorting burns a path through the MOV so it degrades over time. Eventually it cannot handle a spike and can short for too long before completely opening. The high current during the extended short causes fires. Hopefully if you have a protector using old MOV technology that it also is fused to cut out when the MOV catastrophically shorts to prevent the high current that generates heat and a fire. Alas, again, cheapies using MOVs aren't fused (fuselink or circuit breaker). Some of the better ones put a lamp across the MOV. If the MOV is open (its normal condition) then the lamp is on. If the MOV is shorted, the lamp is off (because there's no voltage across a short). Alas, the lamp being on showing the MOV is open could also mean it has catastrophically failed, shorted and burned into an open condition, and the lamp will be on. The only way to know for sure the MOV is working is by testing it but testing is destructive in that you're shorting and burning out small pieces of the scintered metal within, so don't test too often. Here's some aftermath pictures and videos of cheapie protectors going ablaze: http://www.google.com/search?tbm=isc...protector+fire http://www.youtube.com/watch?v=Q5DieEF0_vw http://www.youtube.com/watch?v=1VZbNmbf2vY http://www.youtube.com/watch?v=arN-rGcejNw (*) (*) This guy really isn't demonstrating spiked voltage that these protectors are supposed to short or absorb; however, remember that the protector is getting zapped many times over its lifetime (before catastrophic failure). Whether the protector gets hot enough to cause a fire or itself burst into flames depends on what components were use inside, insulation, fire retardants, and type of enclosure (the plastic housing could be flammable but then a metallic housing would get hot and catch something on fire against which it pressed, like the carpet, wood desk, etc). If you're going to go cheap on a surge protector/suppressor then don't bother buying one and just get a power strip. Either pay for good protection or don't pay at all. You think it has 14-guage wire in the power strip's cord. Does it really? Did you buy an $80+ surge protector or an under $30 cheapie? The cheapies are often nothing more than an extension cord and that is 18 guage (i.e., lamp cord). Although some sites say 18-guage is okay for a 16A load and 16-guage okay for 22A, I still find cords getting warm enough to detect with my hand that are under these max loads. If the cord feels warm then the cord's wire is undersized. The load ratings are for a free standing wire (in air and by itself), not when you bundle them inside a vinyl case with other wires, run along the carpeting, or shove together with other power wiring behind your desk or entertainment center. Another term for chassis wiring for amperage rating is the free-air amperage rating. Once you bundle the wire with others, the max current rating goes down to about 60%, or less. So your 14-gauge single-wire free-air rating of 32A goes down to 17A when bundled; see http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity. How about the extension cord you used between the wall outlet to the surge protector? Most cheap extension cords are just 18 guage and they'll get warm or hot if you use all their outlets for big power devices connected to it. Plus using an extension cord with a surge protector is ALWAYS a no-no. Get a surge protector with a longer cord. 10 feet of power cord can induce a 400V spike during a surge, and then add the length of cord for the power strip. Also, for surge protection, make sure you use the same wall outlet for all protected devices. Don't run a surge protector from one wall outlet to your computer, another surge protector from a different wall outlet to your stereo, and then connect your stereo to your computer. The length of interior wiring between the wall outlets plus the lengths of cords to the surge protector provide an impedence to a voltage spike that can induce high voltage. How many other devices did you have plugged into the same wall outlet that were drawing power? You might only have a 15A circuit for the room. Current load and wire heating is based on the interior wiring to the wall outlets and the fused load for that circuit, not to a bunch of extension cords plugged into the wall outlets. Did you feel if the extension cord was warm? How many into the power strip? Did you feel its cord's temperature to see if it was warm? Did you check the power strip's cord end, each end of the extension cord (just get rid of that to be safe), and the wall outlet for scorch or carbon marks from arcing? Making you have crappy connections. Look at the prongs on the cord ends to make sure they aren't oxidized, corroded, or pitted. You'll need a flashlight to look into the female cord ends and into the wall outlet. Arcing will deteriorate the connection, up the resistance, and the arcing itself makes noise (and blue arcs if it's dark enough in the room). Since you say the computer sits in the middle of the room, were are the power cords routed? Under foot? If so, the constant stepping on them can damage the insulation or connectors and cause shorts. If you cannot route them overhead in a suspended ceiling, through the walls, or under a raised floor then get a cord protector. You slide the cords into the protector which is hard rubber that won't crush underfoot. Use a strong one (http://www.discountramps.com/hdImage...otector-10.jpg) that is heavy-duty and doesn't crush under the weight of you standing on it with both feet. The lightweight soft vinyl cheapies (http://ak.buy.com/PI/0/500/205675672.jpg) are just for show to tidy up a room's look and do nothing to prevent damage to walked-on power cords since the protector crushes to then crush the cords within. Of course, this means you'll be tripping over the sturdy cord protector if it's in an well travelled area and why some are bright yellow so you don't forget it's there. Check for any frays (scrapped off insulation) on the cords? Got mice in the house? They chew on wiring insulation inside the walls. Squirrels, too. If you have GFI outlets, did you check if they popped? Like you guys have said, the pop is pretty good sign that a cap died. The mobo doesn't look like it has a bad cap, that gives the PS more weight as the problem. Since you say it works upstairs and not downstairs, I'm now thinking you have a bad surge protector, damaged cords, blown GFI outlet, slightly shorting near-blown fuse, or some wiring problem downstairs. OK. I will ship the PS back. Thanks |
#8
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Computer popped
Metspitzer wrote:
On Sun, 1 Jul 2012 04:09:00 -0500, VanguardLH wrote: Metspitzer wrote: I took the machine back down stairs and hooked it up. It didn't work. The location is in the center of a very large room. There only outlets are along the wall. The computer was plugged into a power strip and then a 25 ft drop cord. The drop cord may be 12 Gauge, but I am sure it is at least 14 Gauge. I measured the voltage and it was 119. You measured the voltage where? At the power strip into which you plugged the computer? If so, are you using the same power cord to the computer downstairs that you use upstairs? When you plug the computer's power cord (just that) into the power strip, do you see normal voltage at the end of the computer power cord? How did you measure voltage? With a meter? How about an outlet tester (to make sure the wall outlets are wired correctly)? Is it a grounded outlet? If so, did you test the ground is grounded, like checking continuity to a water pipe? Can you plug a working lamp into the same wall outlet and again into the power strip to make sure the circuit can handle a load? How about a vacuum cleaner? Just because you measure voltage doesn't mean the circuit can handle the current load. I've seen fuses that blew. Normally the metal strip blows apart; however, in one case, there was just a crack in the metal strip and they were touching. So voltage measure fine until I put a load on that circuit whereupon voltage dropped to zero or very low. I could get some things to work, like an LCD clock but a radio or lamp would fail. Check the fuse for that circuit in the downstairs room. If you have breakers, flip the room's breaker twice (off-on-off-on). Does your electrical box have a whole-house surge protector? How about the power strip? Get rid of any surge protectors if possible and use unprotected wiring to power the computer. Surge protectors that use MOVs work by shorting when there is excessive spike voltage. This breaks down the MOV over time. Eventually the MOV fails first by shorting and then burning open (and why MOVs can cause fires in surge protectors if the short isn't quick to blow open). Get rid of the surge protected power strip and use an unprotected one for now. Surge protectors have been determined to cause some house fires. I had a video link at one time that showed what happens to too many so-called [cheapie] surge protectors that are continuously spiked to break down the MOV (in a short time instead of the long time normally experienced by a MOV in shorting the spikes) and the power strip burning up. It was dramatic and scary. See http://www.youtube.com/watch?v=uCqK_2q_Mhg at its 0:50 timemark and again at the 3:00 timemark (the MOV has already been shorting catastrophically for awhile and getting host before you see a fire like what is shown). Most "fires" are internal to the surge protector's case so you might only see some scorching or carbon smudges. Some protectors use fire retardant encased MOVs because of how they catastrophically fail after an excessive number of spikes getting shorted through them. Their description of a MOV as a "sponge" to absorb the spike is wrong. It *shorts* across the pads of the MOV to short the spike to ground although some surge protectors also have MOVs across the hot and neutral to handle those spikes. A coil will absorb and nullify. A MOV shorts. The vast majority of consumer-grade surge protectors are surge arrestors in that they short the spike. Some (more expensive surge *suppressors*) absorb the spike and then span the overage over a longer time. One example of a surge suppressor can be read about at zerosurge.com under their tech info section. A MOV is a ceramic wafer with a metallic scintered screen inside that reduces impedance on a spike (which looks like high frequency). The spike punches (burns) through the screen from one side to the other. There is NO absorbing of the spike. It gets shorted across the MOV. This shorting burns a path through the MOV so it degrades over time. Eventually it cannot handle a spike and can short for too long before completely opening. The high current during the extended short causes fires. Hopefully if you have a protector using old MOV technology that it also is fused to cut out when the MOV catastrophically shorts to prevent the high current that generates heat and a fire. Alas, again, cheapies using MOVs aren't fused (fuselink or circuit breaker). Some of the better ones put a lamp across the MOV. If the MOV is open (its normal condition) then the lamp is on. If the MOV is shorted, the lamp is off (because there's no voltage across a short). Alas, the lamp being on showing the MOV is open could also mean it has catastrophically failed, shorted and burned into an open condition, and the lamp will be on. The only way to know for sure the MOV is working is by testing it but testing is destructive in that you're shorting and burning out small pieces of the scintered metal within, so don't test too often. Here's some aftermath pictures and videos of cheapie protectors going ablaze: http://www.google.com/search?tbm=isc...protector+fire http://www.youtube.com/watch?v=Q5DieEF0_vw http://www.youtube.com/watch?v=1VZbNmbf2vY http://www.youtube.com/watch?v=arN-rGcejNw (*) (*) This guy really isn't demonstrating spiked voltage that these protectors are supposed to short or absorb; however, remember that the protector is getting zapped many times over its lifetime (before catastrophic failure). Whether the protector gets hot enough to cause a fire or itself burst into flames depends on what components were use inside, insulation, fire retardants, and type of enclosure (the plastic housing could be flammable but then a metallic housing would get hot and catch something on fire against which it pressed, like the carpet, wood desk, etc). If you're going to go cheap on a surge protector/suppressor then don't bother buying one and just get a power strip. Either pay for good protection or don't pay at all. You think it has 14-guage wire in the power strip's cord. Does it really? Did you buy an $80+ surge protector or an under $30 cheapie? The cheapies are often nothing more than an extension cord and that is 18 guage (i.e., lamp cord). Although some sites say 18-guage is okay for a 16A load and 16-guage okay for 22A, I still find cords getting warm enough to detect with my hand that are under these max loads. If the cord feels warm then the cord's wire is undersized. The load ratings are for a free standing wire (in air and by itself), not when you bundle them inside a vinyl case with other wires, run along the carpeting, or shove together with other power wiring behind your desk or entertainment center. Another term for chassis wiring for amperage rating is the free-air amperage rating. Once you bundle the wire with others, the max current rating goes down to about 60%, or less. So your 14-gauge single-wire free-air rating of 32A goes down to 17A when bundled; see http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity. How about the extension cord you used between the wall outlet to the surge protector? Most cheap extension cords are just 18 guage and they'll get warm or hot if you use all their outlets for big power devices connected to it. Plus using an extension cord with a surge protector is ALWAYS a no-no. Get a surge protector with a longer cord. 10 feet of power cord can induce a 400V spike during a surge, and then add the length of cord for the power strip. Also, for surge protection, make sure you use the same wall outlet for all protected devices. Don't run a surge protector from one wall outlet to your computer, another surge protector from a different wall outlet to your stereo, and then connect your stereo to your computer. The length of interior wiring between the wall outlets plus the lengths of cords to the surge protector provide an impedence to a voltage spike that can induce high voltage. How many other devices did you have plugged into the same wall outlet that were drawing power? You might only have a 15A circuit for the room. Current load and wire heating is based on the interior wiring to the wall outlets and the fused load for that circuit, not to a bunch of extension cords plugged into the wall outlets. Did you feel if the extension cord was warm? How many into the power strip? Did you feel its cord's temperature to see if it was warm? Did you check the power strip's cord end, each end of the extension cord (just get rid of that to be safe), and the wall outlet for scorch or carbon marks from arcing? Making you have crappy connections. Look at the prongs on the cord ends to make sure they aren't oxidized, corroded, or pitted. You'll need a flashlight to look into the female cord ends and into the wall outlet. Arcing will deteriorate the connection, up the resistance, and the arcing itself makes noise (and blue arcs if it's dark enough in the room). Since you say the computer sits in the middle of the room, were are the power cords routed? Under foot? If so, the constant stepping on them can damage the insulation or connectors and cause shorts. If you cannot route them overhead in a suspended ceiling, through the walls, or under a raised floor then get a cord protector. You slide the cords into the protector which is hard rubber that won't crush underfoot. Use a strong one (http://www.discountramps.com/hdImage...otector-10.jpg) that is heavy-duty and doesn't crush under the weight of you standing on it with both feet. The lightweight soft vinyl cheapies (http://ak.buy.com/PI/0/500/205675672.jpg) are just for show to tidy up a room's look and do nothing to prevent damage to walked-on power cords since the protector crushes to then crush the cords within. Of course, this means you'll be tripping over the sturdy cord protector if it's in an well travelled area and why some are bright yellow so you don't forget it's there. Check for any frays (scrapped off insulation) on the cords? Got mice in the house? They chew on wiring insulation inside the walls. Squirrels, too. If you have GFI outlets, did you check if they popped? Like you guys have said, the pop is pretty good sign that a cap died. The mobo doesn't look like it has a bad cap, that gives the PS more weight as the problem. Since you say it works upstairs and not downstairs, I'm now thinking you have a bad surge protector, damaged cords, blown GFI outlet, slightly shorting near-blown fuse, or some wiring problem downstairs. OK. I will ship the PS back. Thanks Is "PS" supposed to be PSU (power supply unit) or "SP" for surge protector? Have you looked at the surge protector yet? Is it switched on? Did it circuit breaker pop? Does anything else work when it's plugged into that surge protector? |
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Computer popped
On Sun, 1 Jul 2012 07:58:07 -0500, VanguardLH wrote:
Metspitzer wrote: On Sun, 1 Jul 2012 04:09:00 -0500, VanguardLH wrote: Metspitzer wrote: I took the machine back down stairs and hooked it up. It didn't work. The location is in the center of a very large room. There only outlets are along the wall. The computer was plugged into a power strip and then a 25 ft drop cord. The drop cord may be 12 Gauge, but I am sure it is at least 14 Gauge. I measured the voltage and it was 119. You measured the voltage where? At the power strip into which you plugged the computer? If so, are you using the same power cord to the computer downstairs that you use upstairs? When you plug the computer's power cord (just that) into the power strip, do you see normal voltage at the end of the computer power cord? How did you measure voltage? With a meter? How about an outlet tester (to make sure the wall outlets are wired correctly)? Is it a grounded outlet? If so, did you test the ground is grounded, like checking continuity to a water pipe? Can you plug a working lamp into the same wall outlet and again into the power strip to make sure the circuit can handle a load? How about a vacuum cleaner? Just because you measure voltage doesn't mean the circuit can handle the current load. I've seen fuses that blew. Normally the metal strip blows apart; however, in one case, there was just a crack in the metal strip and they were touching. So voltage measure fine until I put a load on that circuit whereupon voltage dropped to zero or very low. I could get some things to work, like an LCD clock but a radio or lamp would fail. Check the fuse for that circuit in the downstairs room. If you have breakers, flip the room's breaker twice (off-on-off-on). Does your electrical box have a whole-house surge protector? How about the power strip? Get rid of any surge protectors if possible and use unprotected wiring to power the computer. Surge protectors that use MOVs work by shorting when there is excessive spike voltage. This breaks down the MOV over time. Eventually the MOV fails first by shorting and then burning open (and why MOVs can cause fires in surge protectors if the short isn't quick to blow open). Get rid of the surge protected power strip and use an unprotected one for now. Surge protectors have been determined to cause some house fires. I had a video link at one time that showed what happens to too many so-called [cheapie] surge protectors that are continuously spiked to break down the MOV (in a short time instead of the long time normally experienced by a MOV in shorting the spikes) and the power strip burning up. It was dramatic and scary. See http://www.youtube.com/watch?v=uCqK_2q_Mhg at its 0:50 timemark and again at the 3:00 timemark (the MOV has already been shorting catastrophically for awhile and getting host before you see a fire like what is shown). Most "fires" are internal to the surge protector's case so you might only see some scorching or carbon smudges. Some protectors use fire retardant encased MOVs because of how they catastrophically fail after an excessive number of spikes getting shorted through them. Their description of a MOV as a "sponge" to absorb the spike is wrong. It *shorts* across the pads of the MOV to short the spike to ground although some surge protectors also have MOVs across the hot and neutral to handle those spikes. A coil will absorb and nullify. A MOV shorts. The vast majority of consumer-grade surge protectors are surge arrestors in that they short the spike. Some (more expensive surge *suppressors*) absorb the spike and then span the overage over a longer time. One example of a surge suppressor can be read about at zerosurge.com under their tech info section. A MOV is a ceramic wafer with a metallic scintered screen inside that reduces impedance on a spike (which looks like high frequency). The spike punches (burns) through the screen from one side to the other. There is NO absorbing of the spike. It gets shorted across the MOV. This shorting burns a path through the MOV so it degrades over time. Eventually it cannot handle a spike and can short for too long before completely opening. The high current during the extended short causes fires. Hopefully if you have a protector using old MOV technology that it also is fused to cut out when the MOV catastrophically shorts to prevent the high current that generates heat and a fire. Alas, again, cheapies using MOVs aren't fused (fuselink or circuit breaker). Some of the better ones put a lamp across the MOV. If the MOV is open (its normal condition) then the lamp is on. If the MOV is shorted, the lamp is off (because there's no voltage across a short). Alas, the lamp being on showing the MOV is open could also mean it has catastrophically failed, shorted and burned into an open condition, and the lamp will be on. The only way to know for sure the MOV is working is by testing it but testing is destructive in that you're shorting and burning out small pieces of the scintered metal within, so don't test too often. Here's some aftermath pictures and videos of cheapie protectors going ablaze: http://www.google.com/search?tbm=isc...protector+fire http://www.youtube.com/watch?v=Q5DieEF0_vw http://www.youtube.com/watch?v=1VZbNmbf2vY http://www.youtube.com/watch?v=arN-rGcejNw (*) (*) This guy really isn't demonstrating spiked voltage that these protectors are supposed to short or absorb; however, remember that the protector is getting zapped many times over its lifetime (before catastrophic failure). Whether the protector gets hot enough to cause a fire or itself burst into flames depends on what components were use inside, insulation, fire retardants, and type of enclosure (the plastic housing could be flammable but then a metallic housing would get hot and catch something on fire against which it pressed, like the carpet, wood desk, etc). If you're going to go cheap on a surge protector/suppressor then don't bother buying one and just get a power strip. Either pay for good protection or don't pay at all. You think it has 14-guage wire in the power strip's cord. Does it really? Did you buy an $80+ surge protector or an under $30 cheapie? The cheapies are often nothing more than an extension cord and that is 18 guage (i.e., lamp cord). Although some sites say 18-guage is okay for a 16A load and 16-guage okay for 22A, I still find cords getting warm enough to detect with my hand that are under these max loads. If the cord feels warm then the cord's wire is undersized. The load ratings are for a free standing wire (in air and by itself), not when you bundle them inside a vinyl case with other wires, run along the carpeting, or shove together with other power wiring behind your desk or entertainment center. Another term for chassis wiring for amperage rating is the free-air amperage rating. Once you bundle the wire with others, the max current rating goes down to about 60%, or less. So your 14-gauge single-wire free-air rating of 32A goes down to 17A when bundled; see http://wiki.xtronics.com/index.php/Wire-Gauge_Ampacity. How about the extension cord you used between the wall outlet to the surge protector? Most cheap extension cords are just 18 guage and they'll get warm or hot if you use all their outlets for big power devices connected to it. Plus using an extension cord with a surge protector is ALWAYS a no-no. Get a surge protector with a longer cord. 10 feet of power cord can induce a 400V spike during a surge, and then add the length of cord for the power strip. Also, for surge protection, make sure you use the same wall outlet for all protected devices. Don't run a surge protector from one wall outlet to your computer, another surge protector from a different wall outlet to your stereo, and then connect your stereo to your computer. The length of interior wiring between the wall outlets plus the lengths of cords to the surge protector provide an impedence to a voltage spike that can induce high voltage. How many other devices did you have plugged into the same wall outlet that were drawing power? You might only have a 15A circuit for the room. Current load and wire heating is based on the interior wiring to the wall outlets and the fused load for that circuit, not to a bunch of extension cords plugged into the wall outlets. Did you feel if the extension cord was warm? How many into the power strip? Did you feel its cord's temperature to see if it was warm? Did you check the power strip's cord end, each end of the extension cord (just get rid of that to be safe), and the wall outlet for scorch or carbon marks from arcing? Making you have crappy connections. Look at the prongs on the cord ends to make sure they aren't oxidized, corroded, or pitted. You'll need a flashlight to look into the female cord ends and into the wall outlet. Arcing will deteriorate the connection, up the resistance, and the arcing itself makes noise (and blue arcs if it's dark enough in the room). Since you say the computer sits in the middle of the room, were are the power cords routed? Under foot? If so, the constant stepping on them can damage the insulation or connectors and cause shorts. If you cannot route them overhead in a suspended ceiling, through the walls, or under a raised floor then get a cord protector. You slide the cords into the protector which is hard rubber that won't crush underfoot. Use a strong one (http://www.discountramps.com/hdImage...otector-10.jpg) that is heavy-duty and doesn't crush under the weight of you standing on it with both feet. The lightweight soft vinyl cheapies (http://ak.buy.com/PI/0/500/205675672.jpg) are just for show to tidy up a room's look and do nothing to prevent damage to walked-on power cords since the protector crushes to then crush the cords within. Of course, this means you'll be tripping over the sturdy cord protector if it's in an well travelled area and why some are bright yellow so you don't forget it's there. Check for any frays (scrapped off insulation) on the cords? Got mice in the house? They chew on wiring insulation inside the walls. Squirrels, too. If you have GFI outlets, did you check if they popped? Like you guys have said, the pop is pretty good sign that a cap died. The mobo doesn't look like it has a bad cap, that gives the PS more weight as the problem. Since you say it works upstairs and not downstairs, I'm now thinking you have a bad surge protector, damaged cords, blown GFI outlet, slightly shorting near-blown fuse, or some wiring problem downstairs. OK. I will ship the PS back. Thanks Is "PS" supposed to be PSU (power supply unit) or "SP" for surge protector? Have you looked at the surge protector yet? Is it switched on? Did it circuit breaker pop? Does anything else work when it's plugged into that surge protector? I checked those. I was using a multi meter to check the power at the desk. I was an electrician for 20 years. I am a rookie at electronics, but I did check all the power. Nothing tripped except for the computer. The Power Strip light was still on. Monitor, speakers, lamp all still worked. PS = Power Supply When it happened, I didn't try to power the computer back up. I just unplugged everything and brought it up stairs where the light was better and I unplugged everything inside the computer before trying the power supply again. Thanks The pop, I think, is a big clue. I may go ahead and order a Power Supply tester. |
#10
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Computer popped
On Sun, 01 Jul 2012 09:50:48 -0400, Metspitzer
wrote: When it happened, I didn't try to power the computer back up. I just unplugged everything and brought it up stairs where the light was better and I unplugged everything inside the computer before trying the power supply again. Thanks The pop, I think, is a big clue. I may go ahead and order a Power Supply tester. So there was probably something loose in the machine that you fixed by unplugging/replugging. That still doesn't identify what went pop, though. What you learned as an electrician is *MOSTLY* relevant but there are big differences--with computers you care about not abusing the wires. Pushing line power though a wire it doesn't matter if it's a bit roughed up, at worst you'll get a little bit of heat. With computers you're trying to push very high frequencies through wires, kinked wires or wires that got tugged too hard might not carry signals right. Handle things like ethernet and SATA cables with a bit of respect. |
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