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#1
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I think my power supply is dead
Last night, in the middle of a game, my computer just went dead and
refused to boot up. I think the problem may be the power supply (450W, made by "Rhycom" if you've ever heard of them). I've removed the power supply from the case and tried plugging it in and nothing happens. I just want to confirm my theory that the power supply is dead: regular power supplies, when disconnected from everything but power, should still at least whir up their fans, right? Or does the power supply need ot be attached to the mobo for the fans to work (in which case it may not be my power supply that's dead?) Thanks a lot for the help. P.S. And no, I'm not stupid, I made sure the switch was on the "on" position and the circuit set to 110V but still, nothing happened. |
#2
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It takes less time and would have taught more by not removing
supply AND using the so important 3.5 digit multimeter. Procedu Motherboard turns power supply on and off. But controller circuit requires power. When power supply is plugged into wall receptacle, then purple wire (from power supply to motherboard) provides 5.0 volts (within limits of chart). When power button is pressed, then motherboard controller tells power supply to power on. Green wire is above 2.4 volts when power supply should be off. Green wire should measure less than 0.7 volts when power button is pressed - to command power supply on. Three components - power supply, motherboard controller, and power switch. Using meter, discover which is or is not working. Only then were you ready to replace something. Voltage Wire Color Min V Max V +5 V Red 4.75 V 5.25 V -5 V White -4.75 V -5.25 V +12 V Yellow 11.4 V 12.6 V -12 V Blue -11.4 V -12.6 V +3.3 V Orange 3.135 V 3.465 V +5VSB Purple 4.75 5.25 !Power On Green 0.8 2.0 Power OK Gray 2.4 when power is good BTW, if you did not pull plug from wall receptacle before removing supply, then motherboard failure is a new possibility. Cyde Weys wrote: Last night, in the middle of a game, my computer just went dead and refused to boot up. I think the problem may be the power supply (450W, made by "Rhycom" if you've ever heard of them). I've removed the power supply from the case and tried plugging it in and nothing happens. I just want to confirm my theory that the power supply is dead: regular power supplies, when disconnected from everything but power, should still at least whir up their fans, right? Or does the power supply need ot be attached to the mobo for the fans to work (in which case it may not be my power supply that's dead?) Thanks a lot for the help. P.S. And no, I'm not stupid, I made sure the switch was on the "on" position and the circuit set to 110V but still, nothing happened. |
#3
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w_tom wrote:
It takes less time and would have taught more by not removing supply AND using the so important 3.5 digit multimeter. I don't have one of those - how much would it cost, where could I get one, and which do you suggest? And how exactly would I use it - attaching one lead of the multimeter to the little metal contacts in the wires coming out of the PSU and the other lead to ... where? Procedu Motherboard turns power supply on and off. But controller circuit requires power. When power supply is plugged into wall receptacle, then purple wire (from power supply to motherboard) provides 5.0 volts (within limits of chart). When power button is pressed, then motherboard controller tells power supply to power on. Green wire is above 2.4 volts when power supply should be off. Green wire should measure less than 0.7 volts when power button is pressed - to command power supply on. Three components - power supply, motherboard controller, and power switch. Using meter, discover which is or is not working. Only then were you ready to replace something. Voltage Wire Color Min V Max V +5 V Red 4.75 V 5.25 V -5 V White -4.75 V -5.25 V +12 V Yellow 11.4 V 12.6 V -12 V Blue -11.4 V -12.6 V +3.3 V Orange 3.135 V 3.465 V +5VSB Purple 4.75 5.25 !Power On Green 0.8 2.0 Power OK Gray 2.4 when power is good BTW, if you did not pull plug from wall receptacle before removing supply, then motherboard failure is a new possibility. No, I definitely always totally unplug everything from my box before opening it up and screwing around with the insides. Also, the physical location of my box (on a high shelf above my desk) and its length from the power outlet makes it a near physical impossibility to work on the machine while it is still plugged in. By the way, thanks for the quick and thorough reply. I'm going to get a new power supply this weekend anyway - if it fixes the problem, great, if not, I can stick it in one of my other machines that I think may be suffering from less current. |
#4
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On Thu, 05 Feb 2004 20:04:59 -0500, Cyde Weys wrote:
Last night, in the middle of a game, my computer just went dead and refused to boot up. I think the problem may be the power supply (450W, made by "Rhycom" if you've ever heard of them). I've removed the power supply from the case and tried plugging it in and nothing happens. I just want to confirm my theory that the power supply is dead: regular power supplies, when disconnected from everything but power, should still at least whir up their fans, right? Or does the power supply need ot be attached to the mobo for the fans to work (in which case it may not be my power supply that's dead?) Thanks a lot for the help. P.S. And no, I'm not stupid, I made sure the switch was on the "on" position and the circuit set to 110V but still, nothing happened. Ummm, i recommend you break your policy about opening it, and open it. Check the fan, see if it's siezed... IIRC they used crap sleeve-bearing fans. It's a junk power supply, but, LOL, you could probably fix it by replacing the fan and the output capacitors... I can't be sure that's the problem, but it's by far the most common failure point on those generics. To address your question, a power supply needs a load, at least on it's 5V lead... some have this load integrated as a power resistor, actually almost all do these days, but who knows what gets cut from the design when they start minimizing the design cost. In any case, attaching a hard drive is enough, then when you short the PS_ON, green wire to ground, it should work, if it will. Note that if it's failed, the output may be bad, you don't want to be attaching a "good" hard drive for this test. |
#5
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kony wrote:
On Thu, 05 Feb 2004 20:04:59 -0500, Cyde Weys wrote: Last night, in the middle of a game, my computer just went dead and refused to boot up. I think the problem may be the power supply (450W, made by "Rhycom" if you've ever heard of them). I've removed the power supply from the case and tried plugging it in and nothing happens. I just want to confirm my theory that the power supply is dead: regular power supplies, when disconnected from everything but power, should still at least whir up their fans, right? Or does the power supply need ot be attached to the mobo for the fans to work (in which case it may not be my power supply that's dead?) Thanks a lot for the help. P.S. And no, I'm not stupid, I made sure the switch was on the "on" position and the circuit set to 110V but still, nothing happened. Ummm, i recommend you break your policy about opening it, and open it. Check the fan, see if it's siezed... IIRC they used crap sleeve-bearing fans. It's a junk power supply, but, LOL, you could probably fix it by replacing the fan and the output capacitors... I can't be sure that's the problem, but it's by far the most common failure point on those generics. I'll check the fan and see if it's seized, but no way in hell am I gonna screw around with replacing capacitors ... it's just too risky. At that point I'd just buy a new power supply. To address your question, a power supply needs a load, at least on it's 5V lead... some have this load integrated as a power resistor, actually almost all do these days, but who knows what gets cut from the design when they start minimizing the design cost. In any case, attaching a hard drive is enough, then when you short the PS_ON, green wire to ground, it should work, if it will. Note that if it's failed, the output may be bad, you don't want to be attaching a "good" hard drive for this test. By shorting green wire to ground, you mean get a short wire and stick it into the two appropriate square holes in the mobo connector, right? Does it have to be a hard drive for this purpose - I don't have any expendable hard drives laying around. I could use an optical drive or a floppy drive though, will that work? |
#6
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On Thu, 05 Feb 2004 22:00:52 -0500, Cyde Weys wrote:
I'll check the fan and see if it's seized, but no way in hell am I gonna screw around with replacing capacitors ... it's just too risky. At that point I'd just buy a new power supply. Well that's your call, I just mentioned it as the procedure I've used, which is the most common problem, and solution. To address your question, a power supply needs a load, at least on it's 5V lead... some have this load integrated as a power resistor, actually almost all do these days, but who knows what gets cut from the design when they start minimizing the design cost. In any case, attaching a hard drive is enough, then when you short the PS_ON, green wire to ground, it should work, if it will. Note that if it's failed, the output may be bad, you don't want to be attaching a "good" hard drive for this test. By shorting green wire to ground, you mean get a short wire and stick it into the two appropriate square holes in the mobo connector, right? Does it have to be a hard drive for this purpose - I don't have any expendable hard drives laying around. I could use an optical drive or a floppy drive though, will that work? Yes, with the power supply disconnected from everything but a worthless hard drive (or substitute your choice of load, an old hard drive is something easily understood by everyone), use a jumper wire, paperclip, whatever, to connect pin 14, PS_ON (usually a green wire) to any ground, either a black wire or the power supply metal casing. An optical drive should work, but I don't recall the power consumption of a floppy drive. A "dead" motherboard will usually work too, so long as it isn't shorted out, or an automobile tail light bulb, costs about 50 cents at an auto parts store, but requies the odd parts, a socket or soldering. The multimeter/voltage meter w_tom mentioned can be found just about anywhere... a hardware store, possibly Wall-Mart, K-Mart, Radio Shack, certainly hundreds of places online, etc. It need not be expensive for the level of accuracy required for this purpose, a cheap $10 unit will do fine, though these days most people prefer the digital over the analog type, and they are cheaper to operate in the long run if they accept AA or 9V battery, not a rarer, more costly size. They run a long time on a pair of alkaline AA, several years if you don't use it very often, the shelf life of the batteries would determine their lifespan. |
#7
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Okay, I did what you suggested and the fan in the power supply whirs for
a fraction of a second, does maybe one rotation, and then dies. This is repeatable. So what do I do now? It sounds like the power supply is indeed at fault. |
#8
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Cyde Weys wrote:
Okay, I did what you suggested and the fan in the power supply whirs for a fraction of a second, does maybe one rotation, and then dies. This is repeatable. So what do I do now? It sounds like the power supply is indeed at fault. Okay, I violated my own policy and opened up the power supply. I can't see anything obviously wrong with it (not that I necessarily know what I'm looking for). The fan isn't clogged with dust and turns very easily even when I just blow on it. Anything else I should do before I get me a new power supply? |
#9
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On Thu, 05 Feb 2004 23:33:13 -0500, Cyde Weys wrote:
Okay, I did what you suggested and the fan in the power supply whirs for a fraction of a second, does maybe one rotation, and then dies. This is repeatable. So what do I do now? It sounds like the power supply is indeed at fault. To verify, you had a load attached? Many power supplies that need an external load, would do just that, power on only long enough to stir the fan, then shut off. Assuming you did have the optical drive attached, that would indicate a failure of the power supply. Confirmation would be obtained by testing it, as w_tom mentioned, taking the voltage readings would be something I'd advise if you'd had a voltage meter handy. Then again, I already knew those were junk power supplies, so if spending the least amount of $ was the goal I'd put the $10 for a voltage meter towards a better power supply rather than chancing it on that one at this point. Then again, a multimeter is a handy tool to have, the more you learn/do/etc, the more likely you'll have another need for one. Even if you don't want to repair it, opening it (after unplugged from AC for a minute or two) will probably reveal what failed... more often than not there's visual sign of the failed component(s). |
#10
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kony wrote:
To verify, you had a load attached? Many power supplies that need an external load, would do just that, power on only long enough to stir the fan, then shut off. Yeah, I had a load attached. Assuming you did have the optical drive attached, that would indicate a failure of the power supply. Confirmation would be obtained by testing it, as w_tom mentioned, taking the voltage readings would be something I'd advise if you'd had a voltage meter handy. Then again, I already knew those were junk power supplies, so if spending the least amount of $ was the goal I'd put the $10 for a voltage meter towards a better power supply rather than chancing it on that one at this point. Then again, a multimeter is a handy tool to have, the more you learn/do/etc, the more likely you'll have another need for one. I'm gonna get a multimeter anyway. It's definitely a useful tool to have around that no hardware geek should be without. Even if you don't want to repair it, opening it (after unplugged from AC for a minute or two) will probably reveal what failed... more often than not there's visual sign of the failed component(s). I opened it and I wasn't able to see anything indicating a failure. |
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