I currently have the motherboard of a Dell XPS 8930 in a Thermaltake CTE T500 case with a Corsair CX750M power supply.
The machine complains about a defective power switch cable on boot, because the Thermaltake’s power button does not have the special Dell magic - but it had been running fine like that for months.
Recently, however, the machine has been rebooting once or twice a day, most of the time when I am not around - either in the middle of the night, or while I am at work.
I was in front of it once when it happened: The screen turned black for a moment, then the machine booted up. It was as though someone had pressed the reset button. The reset button, by the way is not connected, but the cable is tied away safely, and can definitely not touch any metal parts.
This started right after my UPS died; I had the PC plugged into the wall for a while, and that was when it happened first. It is now plugged into a UPS again, but that did not make a difference.
This far, I’ve verified that all connectors are firmly seated (including RAM and the video card) and reinstalled the OS. I’ve visually inspected the motherboard - no bulging capacitors or similarly scary stuff as far as I can tell.
I guess the next step would be to replace the power supply. It is quite new, but I suppose it could have gotten damaged, or just be a lemon.
Any cool ideas for other things I could try before I do this?
For mysterious undiagnosable seemingly hardware related issues, the power supply is always a good place to start.
Be aware that Dell has a nasty habit of using “proprietary” power supplies that have the pins switched around on the ATX connector, and thus won’t work unless you either buy one of their stupid OEM supplies or get a pinout chart and rearrange the pins on your new supply before you plug it in. I don’t know if that model is one of the ones that does this, so you might want to check first before you potentially smoke your board.
Every once in a while my machine requires cleaning, not just reseating, the RAM and/or video card edge connectors and slots for no readily identifiable reason. I have no idea how any kind of crud or oxidation manages to accumulate in there given that my PC never moves, it’s not in an especially humid environment nor one with temperature fluctuations, and as far as I can tell the air in here is acceptably clean. But it does nevertheless, and when it gets into that mode it will randomly reboot or blue screen with no rhyme or reason until I remember to hose everything down with CRC contact cleaner. I have to do this once about every 2-3 years. (Yes, I have had this build long enough for this to happen more than once…)
I guess I’ll get a new power supply over the weekend. Seeing as this one already wasn’t OEM, I’ll hope that I’ll get away with something generic. This machine is not new (nor are the RAM or the video card), so maybe cleaning everything while I have it open would be a good idea. Thanks.
what happened to cause the ups to fail? could it have sent a surge or spike through to the system?
also:
suggests that that system needs at least 25a on +5v. your cx750m is only 20a.
but i would be more inclined to think that ‘something’ happened when the ups went.
When I went to work, the UPS was fine, when I came back, it was beeping and blinking. I assumed battery failure - it was a relatively cheap one without useful diagnostic output. Well, I’ll hope that whatever it was only damaged the power supply - and make sure that the replacement does 25A. Thanks.
OK, wow. I checked around a little bit, and the 25A@5V PSU seems to have gone the way of the dodo. If I can’t get a stable system with a 20A@5V PSU, this project may just have increased in size quite significantly.
