Has my PSU gone bad?

[SmackmYackm]

Quick story and then my problem.

I have a fairly recent build, just over a year old, and the other day my video card (MSI 8800 GTS) takes a dump. So I order a new card, an EVGA GTX 260. Installed the new card and it ran for about half an hour before it started crashing. At first it was only when in game, then after awhile it started doing it after just running windows. I called EVGA, they suggested trying the card in another system. I took the card to a friends house, same thing. There were lines and artifacting and strange characters covering the screen during POST and start up. When when it started to load windows it would blue screen. Called EVGA again, they said RMA it, so I did. I should mention that both cards were displaying very similar symptoms.

Now, while I am with out a functioning gaming machine I've been doing research. I've found some things that seem to suggest that my PSU is causing these problems. Specifically the 12V "rail". I've been building my own systems for awhile now, but I never really learned some the more intricate details such as voltage. This is where you guys come in.

Looking at the voltage monitoring in the BIOS, I have 2 12V monitors, a 24 pin and an 8 pin. If I'm not mistaken the 24 is for the main board and the 8 pin is for the PCIe.

The 24 pin is fluctuation between 11.95v and 11.89v, and the 8 pin is fluctuating between 12.01v and 11.95. The fluctuation is fairly constant. From what I have read, anything lower than 11.90v on either of these may be cause for concern.

Here's my hardware:
Abit IP35 Pro
4G RAM
Intel Core 2 Quad Q6600
Enermax Liberty 500W

Thats about it other than a couple of DVD drives and the old and new graphics cards I mentioned earlier.

Any thoughts?

 

[mgear]

It is a possibility that it's your PSU, but it also sounds like a damaged PCI-E slot. Does everything look normal? Is your PC dusty? What are your temps?

 

[Zero82z]

Voltage can't be accurately measured from the BIOS or any software. You'll have to use a digital multimeter. Follow these instructions: http://www.bfgtech.com/bfgpower/troubleshooting.html

 

[0m3g4]

Voltage can't be accurately measured from the BIOS or any software. You'll have to use a digital multimeter. Follow these instructions: http://www.bfgtech.com/bfgpower/troubleshooting.html

^this
if you want true reading you will have to bust out the good old multi meter, and that will tell you exactly what your 12v rail is getting and you want to measure it from boot up, into windows, then have someone start a stressing program and record the fluctuations from each.

 

[Nenu]

...
The 24 pin is fluctuation between 11.95v and 11.89v, and the 8 pin is fluctuating between 12.01v and 11.95. The fluctuation is fairly constant. From what I have read, anything lower than 11.90v on either of these may be cause for concern.

If there is a large voltage drop between full load and idle, then this test can be useful but that is about it.
A stable voltage matters more than the actual voltage (within limits), this is hard to measure with a voltmeter and even harder if the reports have a large possible variance as from a motherboards own voltage reading.

For example, a worn/aged PSU will drop the voltage more when under load.
What this translates to is that as micro fluctuations in power use occur, the supplied voltage will be going up and down a lot more with a worn PSU.
This lack of voltage stability can cause a crash.

The ATX PSU spec states that products should work at +/-10% of the rated voltage but I dont recommend using a PSU that is 10% out (or even 5%) as it is likely to be on its last legs and you dont want a PSU to die when connected to anything expensive!
+/-10% on 12V is 10.8V to 13.2V.
So as you can see actual voltage level isnt the be all and end all but it can cause/indicate problems.
Note:
Higher voltage will induce more heat in the device being powered and that alone can cause damage or stability issues (power being proportional to the square of the voltage).
Lower voltage is an indication that the PSU "may" be struggling, dont worry if it remains stable (between idle/load) and within 5% of rated voltage, its when it drops a lot under load that it needs looking at.
At first glance, your voltages look fine.

 

[Zero82z]

The ATX PSU spec states that products should work at +/-10% of the rated voltage

It's 5% except for the -12V rail.

 

[Nenu]

It's 5% except for the -12V rail.

Thanks I had a brain fart, -ve voltages are the only ones at +/-10% and they are of no significance here.
+/-5% is correct.