+5V spikes cause shut down

[mithraug]

Here are the specs for my box:

Case: Thermaltake Tsunami VA3000SWA
PSU: ePOWER ZU-650W
MB: ASUS P5N32-SLI Deluxe
CPU: Intel Pentium D 930
CPU Fan: ARCTIC COOLING Freezer 7 Pro
Memory: Patriot 2GB DDR2 SDRAM (Dual Channel)
Video: EVGA GeForce 7600GT 256MB x2 (SLI)
HD: Western Digital Caviar SE16 250GB x2 (striped)

I purchased and assembled the system in May of 2006. Everything worked fine until summer of 2007 when it started shutting down randomly. At first I thought it was overheating since removing the side panel seemed to help. But none of the components seemed to be getting too hot. The warmest area inside the box was the space between the 2 video cards so I purchased a PCI slot fan and put it in between them. This didn't seem to help at all.

So I installed PC Probe II (provided by ASUS). According to PC Probe II the system is not overheating at all. The CPU generally runs between 28C and 35C and the MB runs between 25C and 32C, which is well within the tolerance levels. PC Probe II does show a problem with the +5V. Every 10 to 15 minutes the +5V will spike up to about 5.5 volts. Usually it goes back down a few seconds later. But sometimes it stays high too long and then the machine shuts down. This seems to happen more the warmer the system is.

Additionally, if I move any of the power cables coming the from the PSU (or even touch them) while the system is on it immediately shuts down.

I figure it's a problem with the PSU. Either it's going bad or there is a short/bad connection somewhere which get worse as it heats up and expands. But I don't have another PSU handy to make sure. So, before I bought a new one I thought I'd see if I could get more info from the net.

Thank you for any info you can provide, even if just to confirm my suspicions about the PSU.

[jbennet]

yeah, try a new psu. seems the likely candidate

[caperjack]

Additionally, if I move any of the power cables coming the from the PSU (or even touch them) while the system is on it immediately shuts down.

you trouble shot and found your problem and you are risking ruining your computer to find out more info on the net .Get that PSU out now before its to late .

[jbennet]

yeah, dont run your system

on some PSUs (my icute one) theres a sensor that must be attatched to the psu, for the voltage regulation to work. Ensure that is attatched.

[mithraug]

Thanks for the replies. I will replace the PSU and let you know the results.

BTW - I am not risking my computer trying to get more info about the problem from the net as I am doing this from a different computer. Of course... the fact that I continued running the machine even after it first started doing the whole shut-down thing almost a year ago is another issue...

[caperjack]

Of course... the fact that I continued running the machine even after it first started doing the whole shut-down thing almost a year ago is another issue...

it sure is ,if it been that long then maybe its a software issue ,have you tried doing a chkdsk repair .right click on the harddrive icon in mycomputer and go to tools and do it from there check of to fix errors

[mithraug]

Well, thank you for confirming my suspicions about the PSU. I replaced it yesterday (which was a pain, had to remove the CPU heatsink and fan) and now the system is running great. No more shutdowns, no +5V spikes, and I was even able to remove the PCI slot fan and close the side panel (which makes the machine run a lot quieter).

It's weird that I was able to run it for so long with a seemingly bad PSU without permanently damaging something. Anyway, thanks again. This issue is resolved.

[jbennet]

which was a pain, had to remove the CPU heatsink and fan

wtf, was it a nonstandard case or something?

[mithraug]

Well... I dunno about the case being nonstandard. The cpu heatsink and fan are nonstandard though.

Basically the case has a spot at the top where the PSU sits (like most cases I have seen). It is supported by 2 aluminum shelves, a long one on the right side of the case (the side panel that doesn't come off) and a smaller one on the left side of the case. The smaller shelf is attached to a bar that runs all the way from the back of the case to the front of the case. This bar keeps the PSU from going in/coming out on the side. In order to put the PSU in place it has to slide in from underneath, then back to sit on the shelves and then fastened to the back of the case to hold it in place.

The problem I ran into is that because of the positioning of the CPU on the motherboard, the heatsink and fan get in the way of sliding the PSU in and out from the bottom. In actuality I didn't want to remove them from the CPU (didn't wanna mess with the thermal paste and all) so I ended up removing the motherboard with the CPU, heatsink & fan all still in place. I really wish there had been a way to remove that bar so the PSU could be installed from the side rather than the bottom but it was riveted in place.

[caperjack]

yeah i think i know that case !
glad to hear you have sorted out ,good computing !