[silvergoat]

I had built a computer a while back with all new components. It had some quirks like the DVD drive would not respond sometimes. It seemed like the power supply was not powering the device. Fast forward to today.

I had ordered a brand new power supply for use in another system, but I remembered the problem with the computer I had built before and decided to check it out again. Downloaded Hardware monitor and I was surprised to see the 12v at 7.5x- I swapped the power supply with the new one I have and then ran the same utility and I was getting similar voltage @ 12v

How likely is it that two brand new power supplies could both be bad. I am going to have to look for a third to throw in there for now.

Is there anything outside of the power supply that would cause such a low 12v line?

The first power supply was a 500w thermaltake and the second was a 600w corsair- both were brand new.

The system itself is:
p5kpl asus board
e3300 (I think) 2.5 Celeron CPU
1 optical drive
1 hard drive
onboard video and PCI wifi card

 

[Wrench97]

Re: 2 power supplies, same problem

Check the voltages and temps in the Bios on the PC health page, software sensor reading programs are often wrong.

 

[silvergoat]

Re: 2 power supplies, same problem

BIOS voltage is 12.2x

seems like it's fine- I guess it's the motherboard's "green" features. It's an EPU board which is supposed to be some kind of power conscious board.

should have given the full name- p5kpl-am epu

 

[Wrench97]

Re: 2 power supplies, same problem

Sudden random shut downs are either Power or heat related, the Temps look good, unless you see CPU temps in the high 60c or higher range and as long as the caps look good I would think power.

 

[Tyree]

Re: 2 power supplies, same problem

Brand & Model of the new PSU?

 

[silvergoat]

Re: 2 power supplies, same problem

Corsair CX600 and the original was a Thermaltake TR2-500NL2NH

I have a third computer- I'm going to check the voltage on the same software (I used both PC Wizard and Hardware Monitor- both showing the 7.5x-7.6x voltages on the 12V rail).

I am going to get a baseline with the PSU inside the third computer and then I'm going to swap them to the new ones that are questionable.

 

[Wrench97]

Re: 2 power supplies, same problem

Use the Bios readings or a digital voltmeter, checking them on a different motherboard is meaningless.

 

[silvergoat]

Re: 2 power supplies, same problem

All 3 power supplies only showed the 7.xx volts in that computer.

In another computer they were 11.9x and in the BIOS, all were 12.2-12.5.

 

[Wrench97]

Re: 2 power supplies, same problem

The Bios is the most accurate reading next to digital voltmeter, 12.5v is a little high and would make that PSU suspect. Did you look at the caps?

 

[silvergoat]

Re: 2 power supplies, same problem

On the 12.5, I was rounding up- I remembered it was in the the 12.4x range, but I wasn't sure----just checked it again, it is 12.42.

On why I haven't checked the caps--- they are new power supplies still under warranty so I do not want to void the warranties on them by opening them. I do have a multimeter, but not at home.

 

[Wrench97]

Re: 2 power supplies, same problem

Check the caps on the motherboard and video card, not the power supply.

 

[greenbrucelee]

Re: 2 power supplies, same problem

yes as said the motherboard. Never open a psu unless you are a qualified electrical engineer. A psu can carry a lethal charge even if it has been completley powered off for months.

 

[jessi11]

Re: 2 power supplies, same problem

Check Ur pc voltages

 

[silvergoat]

Re: 2 power supplies, same problem

I didn't notice anything that looked abnormal on the motherboard.

 

[Wrench97]

Re: 2 power supplies, same problem

Is the only problem that the DVD drive doesn't respond sometimes?

 

[silvergoat]

Re: 2 power supplies, same problem

Yes- as far as I know it hasn't happened recently. It is a computer I built for my mom so the occasional errors I heard of or don't hear of are only her interpretations of them. She has never used a computer before I gave her this one.

The DVD drive thing happened when I had just built it. I had re-used 1 DVD drive from an old computer I had and I believe that is the drive that was malfunctioning. I did re-seat everything and re-wired everything.

It just so happens that I stopped by and had decided to give it another look because I was ordering parts at the time. As soon as I saw the strange 12v reading I took it back and started swapping parts. I noticed that it was reading the same with every PSU.

I did try to call ASUS to see if this was a normal thing when running in Windows considering the "power-saving" category of board, but after 20 minutes of slow and ill-informed support I was put on hold for an hour and eventually hung up the phone.

I have not experienced these problems again except for the voltage reading- everything now seems normal....I can't say that for sure since I have not used it for extended periods of time, and my mom wouldn't know normal function from abnormal.

 

[Wrench97]

Re: 2 power supplies, same problem

It's not a power saving feature, just that the software is misreading the sensors, not uncommon at all any more, the bios reading will be the most accurate second only to a digital voltmeter.

 

[silvergoat]

Re: 2 power supplies, same problem

Thanks for taking some time with this Wrench. I left the new power supply I bought in there anyways....no sense in it going to waste.