Some help with troubleshooting a HP ProDesk 400 G2.5 SFF motherboard please
I am experiencing the following symptoms:
With the device fully assembled when I press the power button, nothing happens at all.
I pulled the power supply from the computer and stuck a paperclip into pins 16 and 17 on the connector causing the power supply to turn on and the fans to start spinning. All of the voltages checked out ok.
With the power supply outside of the case, I plugged it back into the motherboard and tested it again. No change. PC did not turn on.
I put my multimeter in continuity mode and put the black probe on one of the screws that attach the motherboard to the case and probed with the red probe on each of the pins of the motherboard's power connector.
On each of the 3.3v connections, I got a beep.
Does this mean that my 3.3v rail is shorted to ground? I don't know where to go from here. I do have a request for schematics and board view files on another part of this forum.
I did a quick YouTube search and found a video of someone diagnosing a motherboard with the 3.3v power rail shorted to ground and they traced it back to the chipset on the motherboard. Their "proof" was that the caps on the top of the PCH chip would beep when being checked in continuity mode on their multimeter with the black probe on ground and then checking both sides of the caps. My motherboard has the same issue when I perform the same check. Does that mean my PCH chip/chipset is "bad" and shorted to ground? If I removed the chip from the motherboard would that get rid of the short?
In theory, if the PCH chip was bad and I replaced it with a known good one or supposed good one, and as long as nothing else is wrong with the board then it should work then?
Sorry for all of the questions, still a newb!
Thanks in advance for any and all helpful comments.
With the device fully assembled when I press the power button, nothing happens at all.
I pulled the power supply from the computer and stuck a paperclip into pins 16 and 17 on the connector causing the power supply to turn on and the fans to start spinning. All of the voltages checked out ok.
With the power supply outside of the case, I plugged it back into the motherboard and tested it again. No change. PC did not turn on.
I put my multimeter in continuity mode and put the black probe on one of the screws that attach the motherboard to the case and probed with the red probe on each of the pins of the motherboard's power connector.
On each of the 3.3v connections, I got a beep.
Does this mean that my 3.3v rail is shorted to ground? I don't know where to go from here. I do have a request for schematics and board view files on another part of this forum.
I did a quick YouTube search and found a video of someone diagnosing a motherboard with the 3.3v power rail shorted to ground and they traced it back to the chipset on the motherboard. Their "proof" was that the caps on the top of the PCH chip would beep when being checked in continuity mode on their multimeter with the black probe on ground and then checking both sides of the caps. My motherboard has the same issue when I perform the same check. Does that mean my PCH chip/chipset is "bad" and shorted to ground? If I removed the chip from the motherboard would that get rid of the short?
In theory, if the PCH chip was bad and I replaced it with a known good one or supposed good one, and as long as nothing else is wrong with the board then it should work then?
Sorry for all of the questions, still a newb!
Thanks in advance for any and all helpful comments.
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