If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
ASUS P4C800-E Deluxe BIOS Problems
I just RMAed my two week old P4C800-E Deluxe M/B to NewEgg.Com because of
BIOS problems http://helpdesk.asus.com and I couldn't correct. Even after updating to the latest BIOS version, I'd typically get "New CPU Installed" alerts from the BIOS and have to manually reset BIOS data to get the M/B to complete startup. ASUS was concerned about "EMI interference" and/or improper grounding of the M/B to the case and suggested removing the M/B from the case and test with just video card, and keyboard (no memory) on a non-conducting surface (wooden workbench, phone book, or the box the M/B came in) and if this worked reinstall in the case with electricians tape over the metal M/B stand-offs and red-paper washers under the heads of the ten screws that secure the M/B to the Lian-Li M/B tray. The system wouldn't peep or show any life until I installed the RAM. After installing the memory, it'd would fine and the BIOS retaining all the settings. The tape & paper washers seemed to fix the problem (it'd regularly boot to XP w/o incident) until I exchanged the newly assembled PC for my eight year old 200MHz machine. After hooking up things like the phone line, printer, joystick to the game port, and an open-ended serial port cable, the new PC would halt during POST with a "Black Screen". After a few cold reboots, I got a display indicating the BIOS had again halted due to "CPU Overclocking". The maddening thing is that the dam thing would again boot to XP after removing the M/B tray from the case (M/B still bolted to the tray), hooking up the internal stuff (power, HDD, floppies, PCI Modem, video card, and CD-RW devices) and powering up. At that point I said "M/B latent defect" and RMAed it back to the point of sale. Is anyone else have any "EMI interference" and/or improper grounding problem solutions they can share with us along with the workarounds? Patrick |
#2
|
|||
|
|||
In article , "Patrick Martin"
wrote: I just RMAed my two week old P4C800-E Deluxe M/B to NewEgg.Com because of BIOS problems http://helpdesk.asus.com and I couldn't correct. Even after updating to the latest BIOS version, I'd typically get "New CPU Installed" alerts from the BIOS and have to manually reset BIOS data to get the M/B to complete startup. ASUS was concerned about "EMI interference" and/or improper grounding of the M/B to the case and suggested removing the M/B from the case and test with just video card, and keyboard (no memory) on a non-conducting surface (wooden workbench, phone book, or the box the M/B came in) and if this worked reinstall in the case with electricians tape over the metal M/B stand-offs and red-paper washers under the heads of the ten screws that secure the M/B to the Lian-Li M/B tray. The system wouldn't peep or show any life until I installed the RAM. After installing the memory, it'd would fine and the BIOS retaining all the settings. The tape & paper washers seemed to fix the problem (it'd regularly boot to XP w/o incident) until I exchanged the newly assembled PC for my eight year old 200MHz machine. After hooking up things like the phone line, printer, joystick to the game port, and an open-ended serial port cable, the new PC would halt during POST with a "Black Screen". After a few cold reboots, I got a display indicating the BIOS had again halted due to "CPU Overclocking". The maddening thing is that the dam thing would again boot to XP after removing the M/B tray from the case (M/B still bolted to the tray), hooking up the internal stuff (power, HDD, floppies, PCI Modem, video card, and CD-RW devices) and powering up. At that point I said "M/B latent defect" and RMAed it back to the point of sale. Is anyone else have any "EMI interference" and/or improper grounding problem solutions they can share with us along with the workarounds? Patrick Grounding and emissions control (EMI prevention) on PCs for me are two of the great mysteries. My first reaction to your post was "too bad the Asus helpdesk didn't go into more detail about just what effect they thought they were fixing", but because English is not their mother tongue, I suppose it would be expecting a lot for them to go into more detail. Grounding is one of my weakness, in that I have a lot of trouble identifying out of many theories, which one might be significant enough to stop a circuit from working. Therefore, take the rest of this meandering post with a "grain of salt". First of all, Asus course of action sounds "doomed to failure". It is my understanding that establishing the motherboard at ground potential is important to the I/O function. In other words, if you expect to connect external devices to your computer, this won't work reliably unless the motherboard is well grounded. Now, "well enough" grounded might mean that one or two standoffs minimum are conductors that short the motherboard ground rings to the case metal. In the case of the Lian Li, with slideout motherboard tray, the ground path is not quite the same as it would be in a "cheap and cheerful" steel riveted case. In a cheap steel case, it is easy to see how a good ground can be established, as the motherboard tray is fastened to the rest of the case. With a sliding motherboard tray, the metal surfaces would have to be oxide free for good contact. Another ground path is via the metal springs situated around the connector area on the motherboard. These springs are there for the express purpose of establishing a ground around the connectors. I've been taught at work, that "EMI springs" are good for preventing RF leakage around metal openings in a housing, but in the case of the PC, I think the purpose might be for diverting external ground loop currents, so that they cannot upset the ground potential inside the motherboard. For example, say your printer is connected to a different wall outlet than your computer. There could be a difference in the ground potential between the printer and the computer. The cable to the printer is DC connected, and communication relies on the ground reference at the two ends of the cable not being very different. So, the ground path from the green safety ground on the Power Supply, to the connector shroud, is important to the printer cable and I/O working properly. So, when Asus had you isolate the grounding on the motherboard, I don't see that as being very useful to the end objective of having a fully functional PC. Either the design works the way it was intended or it doesn't, and in your case it isn't working. Now, in terms of EMI prevention, everything I've been taught about it is violated in the way that PCs are designed. Motherboards are typically four layer microstrip design, with the conductor layers being signal-ground-power-signal. The exposed signals on the top of the motherboard function as tiny antennas, spewing interference into the air. The proximity of the ground layer inside the motherboard, to the signal conductors, helps attenuate the effect to a certain extent. (In other words, if the board was just two layers signal-signal with no ground, the motherboard wouldn't work and you wouldn't be able to receive radio or TV broadcasts in your house, due to the electical noise generated by the PC.) The next layer of EMI prevention is done at the case level. A proper RF proof case would be a "Faraday cage", a continuous metal cage with no gaps in it, all around the device that needs protection. A PC case has so many holes, bad metal to metal seams, etc., there is no way a PC case can attenuate any kind of emissions. I was taught that emissions and susceptability go hand in hand. Any "antennas" inside the PC, can not only emit RF garbage out into the air, they can also pick up garbage from other devices. You might see the effects of this, if your PC crashes every time a noisy electrical device is used nearby (vacuum cleaner motor, electric drill motor etc). So based on this small knowledge of grounding, I'm at a loss as to just what Asus hoped to achieve by reducing the grounding. A solid ground path is established through the COM signals on the 20 pin ATX connector, so the motherboard can never be completely isolated. The addition of grounding through the standoffs only serves to add additional ways that return currents can flow back to earth ground, and I would sooner leave those connected than disconnected. I have no idea what kind of defect might exist inside that board. It doesn't sound like anything digital is broken on the board. If you have the time and patience, I'd try installing the motherboard in a cheap steel case without a removable motherboard tray, just to see if it would work in there. About the only thing I can think of, is somehow the Lian Li is upsetting some of the assumptions about how grounding is supposed to work in the PC. Still puzzled, Paul |
#3
|
|||
|
|||
Steve,
Thanks for the response. I think that we are in agreement that the ASUS helpdesk response (it appeared to be a 'caned' response) is what is known in the Air Force as a "goat rope" project, one having little significance or meaning. I think we can rule out the power supply since its a new TruePower550 ATX12V Antec unit (P/N#S40ATX) rated at 550w. My Navy submarine experience taught me to always build in more than ample electrical capacity for growth. I doubt that the memory sticks were the problem since the system would work just fine once I got past the BIOS interactions. My BIOS settings were generic (I generally accepted the default settings except for HHD boot settings) without any attempt to overclock. My guess is that the M/B had a faulty current trace somewhere and it'd open or shut based on mechanical strains on the board shut as going from horizontal on the workbench to rotated 90 degrees during installation in the case. Now if the replacement board has the same problem, I'll return to the electrical grounding theories. I don't know exactly what's going on inside the power supply, but I'd bet that both rectified DC and the input 60 Hz have a common ground reference back to the ground plug on the power cable. The M/B has many "Common" connections back to the power supply. So, my uneducated guess is that the washers and tape is approach is an ASUS helpdesk "urban legend". Probably a better idea would be to remove the tape and electrically ground the whole case to the house ground (thru a power strip ground pin?). Come back? -pgm "Steve Sr." wrote in message ... I just RMA'd the same brand-new board to Newegg.com because the PS/2 mouse port wouldn't function and the PS/2 keyboard was flakey. If you think Windows is flakey by itself put it on flakey hardware and you'll pull out all of your hair! For EMI it is better to ground ALL of the mounting screws as this adds an additional return path for high speed signals. I don't think Asus guys know what they were talking about unless they know they already have a design problem they are trying to get around. I would also look at your power supply. The effect of removing or insulating the screws also increases the impedance of the power distribution of the board which will lead to more voltage drop and could explain your different test results if the power supply was running on the low side. At the same time this will also increase any noise on the internal sections of the board which may also cause an issue. What type of power supply do you have? The biggest causes of instability apart from overclocking are memory and power supply issues. HTH, Steve On Sat, 15 Nov 2003 18:44:05 -0500, "Patrick Martin" wrote: I just RMAed my two week old P4C800-E Deluxe M/B to NewEgg.Com because of BIOS problems http://helpdesk.asus.com and I couldn't correct. Even after updating to the latest BIOS version, I'd typically get "New CPU Installed" alerts from the BIOS and have to manually reset BIOS data to get the M/B to complete startup. ASUS was concerned about "EMI interference" and/or improper grounding of the M/B to the case and suggested removing the M/B from the case and test with just video card, and keyboard (no memory) on a non-conducting surface (wooden workbench, phone book, or the box the M/B came in) and if this worked reinstall in the case with electricians tape over the metal M/B stand-offs and red-paper washers under the heads of the ten screws that secure the M/B to the Lian-Li M/B tray. The system wouldn't peep or show any life until I installed the RAM. After installing the memory, it'd would fine and the BIOS retaining all the settings. The tape & paper washers seemed to fix the problem (it'd regularly boot to XP w/o incident) until I exchanged the newly assembled PC for my eight year old 200MHz machine. After hooking up things like the phone line, printer, joystick to the game port, and an open-ended serial port cable, the new PC would halt during POST with a "Black Screen". After a few cold reboots, I got a display indicating the BIOS had again halted due to "CPU Overclocking". The maddening thing is that the dam thing would again boot to XP after removing the M/B tray from the case (M/B still bolted to the tray), hooking up the internal stuff (power, HDD, floppies, PCI Modem, video card, and CD-RW devices) and powering up. At that point I said "M/B latent defect" and RMAed it back to the point of sale. Is anyone else have any "EMI interference" and/or improper grounding problem solutions they can share with us along with the workarounds? Patrick |
#4
|
|||
|
|||
Paul,
Thanks for the response. You've tended to confirm my thoughts that the root cause of my problem is not a electrical (grounding or EMI) problem. I think that the board has a mechanical defect in one of the thousands of circuit traces in/on the board and the simple act of attaching the board to the tray and installing the tray in the case resulted in enough mechanical strain that a circuit was opened intermittently somewhere. Of course if the next board shows the same problem I'll go back to the electrical theories again. Perhaps remove the tape from the standoffs and ground the whole case to the house ground (or buy an UPS). Thanks again, -pgm "Paul" wrote in message ... In article , "Patrick Martin" wrote: I just RMAed my two week old P4C800-E Deluxe M/B to NewEgg.Com because of BIOS problems http://helpdesk.asus.com and I couldn't correct. Even after updating to the latest BIOS version, I'd typically get "New CPU Installed" alerts from the BIOS and have to manually reset BIOS data to get the M/B to complete startup. ASUS was concerned about "EMI interference" and/or improper grounding of the M/B to the case and suggested removing the M/B from the case and test with just video card, and keyboard (no memory) on a non-conducting surface (wooden workbench, phone book, or the box the M/B came in) and if this worked reinstall in the case with electricians tape over the metal M/B stand-offs and red-paper washers under the heads of the ten screws that secure the M/B to the Lian-Li M/B tray. The system wouldn't peep or show any life until I installed the RAM. After installing the memory, it'd would fine and the BIOS retaining all the settings. The tape & paper washers seemed to fix the problem (it'd regularly boot to XP w/o incident) until I exchanged the newly assembled PC for my eight year old 200MHz machine. After hooking up things like the phone line, printer, joystick to the game port, and an open-ended serial port cable, the new PC would halt during POST with a "Black Screen". After a few cold reboots, I got a display indicating the BIOS had again halted due to "CPU Overclocking". The maddening thing is that the dam thing would again boot to XP after removing the M/B tray from the case (M/B still bolted to the tray), hooking up the internal stuff (power, HDD, floppies, PCI Modem, video card, and CD-RW devices) and powering up. At that point I said "M/B latent defect" and RMAed it back to the point of sale. Is anyone else have any "EMI interference" and/or improper grounding problem solutions they can share with us along with the workarounds? Patrick Grounding and emissions control (EMI prevention) on PCs for me are two of the great mysteries. My first reaction to your post was "too bad the Asus helpdesk didn't go into more detail about just what effect they thought they were fixing", but because English is not their mother tongue, I suppose it would be expecting a lot for them to go into more detail. Grounding is one of my weakness, in that I have a lot of trouble identifying out of many theories, which one might be significant enough to stop a circuit from working. Therefore, take the rest of this meandering post with a "grain of salt". First of all, Asus course of action sounds "doomed to failure". It is my understanding that establishing the motherboard at ground potential is important to the I/O function. In other words, if you expect to connect external devices to your computer, this won't work reliably unless the motherboard is well grounded. Now, "well enough" grounded might mean that one or two standoffs minimum are conductors that short the motherboard ground rings to the case metal. In the case of the Lian Li, with slideout motherboard tray, the ground path is not quite the same as it would be in a "cheap and cheerful" steel riveted case. In a cheap steel case, it is easy to see how a good ground can be established, as the motherboard tray is fastened to the rest of the case. With a sliding motherboard tray, the metal surfaces would have to be oxide free for good contact. Another ground path is via the metal springs situated around the connector area on the motherboard. These springs are there for the express purpose of establishing a ground around the connectors. I've been taught at work, that "EMI springs" are good for preventing RF leakage around metal openings in a housing, but in the case of the PC, I think the purpose might be for diverting external ground loop currents, so that they cannot upset the ground potential inside the motherboard. For example, say your printer is connected to a different wall outlet than your computer. There could be a difference in the ground potential between the printer and the computer. The cable to the printer is DC connected, and communication relies on the ground reference at the two ends of the cable not being very different. So, the ground path from the green safety ground on the Power Supply, to the connector shroud, is important to the printer cable and I/O working properly. So, when Asus had you isolate the grounding on the motherboard, I don't see that as being very useful to the end objective of having a fully functional PC. Either the design works the way it was intended or it doesn't, and in your case it isn't working. Now, in terms of EMI prevention, everything I've been taught about it is violated in the way that PCs are designed. Motherboards are typically four layer microstrip design, with the conductor layers being signal-ground-power-signal. The exposed signals on the top of the motherboard function as tiny antennas, spewing interference into the air. The proximity of the ground layer inside the motherboard, to the signal conductors, helps attenuate the effect to a certain extent. (In other words, if the board was just two layers signal-signal with no ground, the motherboard wouldn't work and you wouldn't be able to receive radio or TV broadcasts in your house, due to the electical noise generated by the PC.) The next layer of EMI prevention is done at the case level. A proper RF proof case would be a "Faraday cage", a continuous metal cage with no gaps in it, all around the device that needs protection. A PC case has so many holes, bad metal to metal seams, etc., there is no way a PC case can attenuate any kind of emissions. I was taught that emissions and susceptability go hand in hand. Any "antennas" inside the PC, can not only emit RF garbage out into the air, they can also pick up garbage from other devices. You might see the effects of this, if your PC crashes every time a noisy electrical device is used nearby (vacuum cleaner motor, electric drill motor etc). So based on this small knowledge of grounding, I'm at a loss as to just what Asus hoped to achieve by reducing the grounding. A solid ground path is established through the COM signals on the 20 pin ATX connector, so the motherboard can never be completely isolated. The addition of grounding through the standoffs only serves to add additional ways that return currents can flow back to earth ground, and I would sooner leave those connected than disconnected. I have no idea what kind of defect might exist inside that board. It doesn't sound like anything digital is broken on the board. If you have the time and patience, I'd try installing the motherboard in a cheap steel case without a removable motherboard tray, just to see if it would work in there. About the only thing I can think of, is somehow the Lian Li is upsetting some of the assumptions about how grounding is supposed to work in the PC. Still puzzled, Paul |
#5
|
|||
|
|||
In article , "Patrick Martin"
wrote: Paul, Thanks for the response. You've tended to confirm my thoughts that the root cause of my problem is not a electrical (grounding or EMI) problem. I think that the board has a mechanical defect in one of the thousands of circuit traces in/on the board and the simple act of attaching the board to the tray and installing the tray in the case resulted in enough mechanical strain that a circuit was opened intermittently somewhere. Of course if the next board shows the same problem I'll go back to the electrical theories again. Perhaps remove the tape from the standoffs and ground the whole case to the house ground (or buy an UPS). Thanks again, -pgm If you want a recent known defect in Asus boards, have a look for this. This problem is only supposed to be on the P4C800, but if you happen to have the motherboard out of the case sometime in the future, it wouldn't hurt to inspect for it... "Michael Rudolph posted about a problem with the P4C800 not too long ago. He mentions a post by "MechaBouncer" in this forum. A batch of P4C800 were made with a solder blob underneath the S478 heatsink mounting bracket. This forms a short or partial short, and could be loading your power supply: http://www.techsupportforums.com/sho...=&postid=41955 There is a picture of what it looks like underneath the plastic mounting bracket here. This is a picture of the bottom of the motherboard, with the plastic bracket for the S478 retention removed for inspection. The partial short is in the lower right hand corner. http://koti.mbnet.fi/~nightops/eki/DSC00249.JPG " HTH, Paul "Paul" wrote in message ... In article , "Patrick Martin" wrote: I just RMAed my two week old P4C800-E Deluxe M/B to NewEgg.Com because of BIOS problems http://helpdesk.asus.com and I couldn't correct. Even after updating to the latest BIOS version, I'd typically get "New CPU Installed" alerts from the BIOS and have to manually reset BIOS data to get the M/B to complete startup. ASUS was concerned about "EMI interference" and/or improper grounding of the M/B to the case and suggested removing the M/B from the case and test with just video card, and keyboard (no memory) on a non-conducting surface (wooden workbench, phone book, or the box the M/B came in) and if this worked reinstall in the case with electricians tape over the metal M/B stand-offs and red-paper washers under the heads of the ten screws that secure the M/B to the Lian-Li M/B tray. The system wouldn't peep or show any life until I installed the RAM. After installing the memory, it'd would fine and the BIOS retaining all the settings. The tape & paper washers seemed to fix the problem (it'd regularly boot to XP w/o incident) until I exchanged the newly assembled PC for my eight year old 200MHz machine. After hooking up things like the phone line, printer, joystick to the game port, and an open-ended serial port cable, the new PC would halt during POST with a "Black Screen". After a few cold reboots, I got a display indicating the BIOS had again halted due to "CPU Overclocking". The maddening thing is that the dam thing would again boot to XP after removing the M/B tray from the case (M/B still bolted to the tray), hooking up the internal stuff (power, HDD, floppies, PCI Modem, video card, and CD-RW devices) and powering up. At that point I said "M/B latent defect" and RMAed it back to the point of sale. Is anyone else have any "EMI interference" and/or improper grounding problem solutions they can share with us along with the workarounds? Patrick Grounding and emissions control (EMI prevention) on PCs for me are two of the great mysteries. My first reaction to your post was "too bad the Asus helpdesk didn't go into more detail about just what effect they thought they were fixing", but because English is not their mother tongue, I suppose it would be expecting a lot for them to go into more detail. Grounding is one of my weakness, in that I have a lot of trouble identifying out of many theories, which one might be significant enough to stop a circuit from working. Therefore, take the rest of this meandering post with a "grain of salt". First of all, Asus course of action sounds "doomed to failure". It is my understanding that establishing the motherboard at ground potential is important to the I/O function. In other words, if you expect to connect external devices to your computer, this won't work reliably unless the motherboard is well grounded. Now, "well enough" grounded might mean that one or two standoffs minimum are conductors that short the motherboard ground rings to the case metal. In the case of the Lian Li, with slideout motherboard tray, the ground path is not quite the same as it would be in a "cheap and cheerful" steel riveted case. In a cheap steel case, it is easy to see how a good ground can be established, as the motherboard tray is fastened to the rest of the case. With a sliding motherboard tray, the metal surfaces would have to be oxide free for good contact. Another ground path is via the metal springs situated around the connector area on the motherboard. These springs are there for the express purpose of establishing a ground around the connectors. I've been taught at work, that "EMI springs" are good for preventing RF leakage around metal openings in a housing, but in the case of the PC, I think the purpose might be for diverting external ground loop currents, so that they cannot upset the ground potential inside the motherboard. For example, say your printer is connected to a different wall outlet than your computer. There could be a difference in the ground potential between the printer and the computer. The cable to the printer is DC connected, and communication relies on the ground reference at the two ends of the cable not being very different. So, the ground path from the green safety ground on the Power Supply, to the connector shroud, is important to the printer cable and I/O working properly. So, when Asus had you isolate the grounding on the motherboard, I don't see that as being very useful to the end objective of having a fully functional PC. Either the design works the way it was intended or it doesn't, and in your case it isn't working. Now, in terms of EMI prevention, everything I've been taught about it is violated in the way that PCs are designed. Motherboards are typically four layer microstrip design, with the conductor layers being signal-ground-power-signal. The exposed signals on the top of the motherboard function as tiny antennas, spewing interference into the air. The proximity of the ground layer inside the motherboard, to the signal conductors, helps attenuate the effect to a certain extent. (In other words, if the board was just two layers signal-signal with no ground, the motherboard wouldn't work and you wouldn't be able to receive radio or TV broadcasts in your house, due to the electical noise generated by the PC.) The next layer of EMI prevention is done at the case level. A proper RF proof case would be a "Faraday cage", a continuous metal cage with no gaps in it, all around the device that needs protection. A PC case has so many holes, bad metal to metal seams, etc., there is no way a PC case can attenuate any kind of emissions. I was taught that emissions and susceptability go hand in hand. Any "antennas" inside the PC, can not only emit RF garbage out into the air, they can also pick up garbage from other devices. You might see the effects of this, if your PC crashes every time a noisy electrical device is used nearby (vacuum cleaner motor, electric drill motor etc). So based on this small knowledge of grounding, I'm at a loss as to just what Asus hoped to achieve by reducing the grounding. A solid ground path is established through the COM signals on the 20 pin ATX connector, so the motherboard can never be completely isolated. The addition of grounding through the standoffs only serves to add additional ways that return currents can flow back to earth ground, and I would sooner leave those connected than disconnected. I have no idea what kind of defect might exist inside that board. It doesn't sound like anything digital is broken on the board. If you have the time and patience, I'd try installing the motherboard in a cheap steel case without a removable motherboard tray, just to see if it would work in there. About the only thing I can think of, is somehow the Lian Li is upsetting some of the assumptions about how grounding is supposed to work in the PC. Still puzzled, Paul |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Problems with SoundStorm on Asus A7N8X Deluxe | Naj | General | 0 | January 5th 04 02:14 AM |
asus P4C800 and raid problems | Gianluca_Venezia | Asus Motherboards | 0 | October 21st 03 10:48 PM |
Restore BIOS defaults on ASUS A7N8X Deluxe mb? | K Sundberg | Overclocking AMD Processors | 2 | October 11th 03 03:31 PM |
what is the best BIOS settings for the P4C800 Deluxe? | xxxDanielxxx | Asus Motherboards | 0 | July 14th 03 12:17 AM |
New beta bios P4C800 Deluxe | J. Allen | Asus Motherboards | 3 | June 30th 03 04:06 AM |