PSU issues usually manifest themselves under heavy load, not when you boot the machine.

It's likely that the video card is dead.

Difficult to know if you can't diagnose the problem. I have tons of spare hardware laying around. If something is giving me problems, then it's time to start pulling it apart (IF I don't have a good suspicion of what the problem is).

Zup wrote:

Yesterday I was playing with my PC when it shut off without any warning. I tried to power on, but it didn't worked... no image, no POST beeps, nothing.

Did the case fans, case light, and PSU fan still come on?

You can always take the PSU to your friendly local PC dealership and politely ask them to plug it into a tester - but that won't tell you if the PSU is having problems under heavy load.

What brand is your PSU anyway?

The PC is "repaired" (or at least functional) with an older 7600. Fans were running at full power and case light lit. Hard disks and optical drivers worked, also. I suspected that something connected to PCI bus (or the RAM) was failing, and it seemed like something overheated.

The first step was disconnecting every PCI card, and it was the video card. Because modern video cards need so much power, I asked about the power supply.

I think the PSU is a 600W Tacens, but my memory may be failing.

There are some manufacturers of both passive and active PSU testers.

They connect up to some of the connector ends and then test the static output voltages and notate if any rails are missing.

Of course the active testers are more expensive as they test under load.

I like the passive testers for checking if any PS voltage rails are missing, this will help diagnose any faults there.

Your description of the issues do seem to indicate a Video Card issue, i.e., it was overheating and drawing more and more power which caused the PSU to shutdown to prevent any further damage.

Last night my brother had an issue with his machine, however, his machine would power on, but no video and no boot cycle.

We traced it down to the video card as well, in his case he needed to clean out the ducted fan section of the card and the inside of his computer case, reconnected and it worked fine.

Did a chkdsk /f afterwards to fix any filesystem issues and it appears he is back online once again.

Sounds like the PSU did its job and OverCurrentProtect (OCP) kicked in and shut the PSU down when the card went out.

Why do you think your memory is failing?

As I have never heard of Tacens before (not known name brand), It COULD be a failing PSU, since the 7900GS will draw more current than a 7600GT and might be just allieviating the real issue with less power draw.

Why not test the system out with full load and see if it shuts down again, Try Prime95 stresstest and Furmark at the same time to get a better load on the PSU.

Only other way to test would be to get a PSU tester that would put full load on the PSU which would IMO be a waste of money since I bet that Tacen was a cheapie.

What are your full system specs? This maybe used with a PSU calculator to see what loads you might of been putting on that 600watter.

He thinks his memory is failing because he cant remember the brand of psu he has

ps: its tagen and they are a good brand

pps: you can see if its dead or not with a paperclip
http://aphnetworks.com/lounge/turn_on_psu_wit … paperclip_trick

Davros wrote:

He thinks his memory is failing because he cant remember the brand of psu he has […]
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He thinks his memory is failing because he cant remember the brand of psu he has

ps: its tagen and they are a good brand

pps: you can see if its dead or not with a paperclip
http://aphnetworks.com/lounge/turn_on_psu_wit … paperclip_trick

You mean Tagan? Iirc those PSU's did have problems with caps going bad. I have a 380W one myself and so far, it's working perfectly in my 3200+ Barton build.

RogueTrip2012 wrote:

Sounds like the PSU did its job and OverCurrentProtect (OCP) kicked in and shut the PSU down when the card went out.

But if the PSU shut down, then the fans would have stopped running along with the case lights, right? Or is that not how OCP works?

How exactly does it work, anyway? I'm not trying to imply I have the slightest clue. Do you mean when the card failed, it started drawing more power than it should?

Yep, my memory definitely failed... the PSU was a Xilence (600W).

The PSU works, but I know that PSUs can give less power when they're getting older; and some graphic cards won't boot if the PSU has not enough power (although it gives enough power for 2D desktop).

I had a PSU that overheated when I changed graphic cards (it failed about 30 minutes of 3D use), and when protections kick in the PSU won't restart until some time passes (10 minutes)... I think that OCP works the same (the PSU won't start for some time).