Troubleshooting - PSU, Mobo or CPU?

northun_munky · 12 Mar 2013 at 08:06

My PC went bang and went dead on Sunday whilst I was playing a game. (Spec is in my sig) I couldn't see or smell any smoke coming from it and the led's on the motherboard were still lit. When I tried to turn it on all i got was a twitch of the fans (both psu and case fans) and a code of 8.2 of the post indicater. This means Enable ATX power supply according to the manual. I've tried it with only one stick of ram and also tried a different graphics card to no avail.

I've jumped the PSU with only the fans and HDD connected and it appears to work fine. The fans spin up and such. To be sure I borrowed a PSU from my mates rig and i still get the same problem. I'm thinking blown PSU for sure?

Weirdly though, if I disconnect the 8 pin 12v cpu power connecter and the graphics card the pc will power on and stop at code 8.7, which is check CPU core voltage.

Is It possible that the cpu is blown? Or is it more likely that if its not the PSU it might be the motherboard? I did read somewhere on here that if a PSU does go it still can put out enough power to spin the fans and lights on the mobo but fail when trying to pull a greater load?

Any advice would be greatly appreciated. I'm going to try to borrow another PSU today just to be sure on that front as swapping CPU's and Mobos would be more of a ball ache as I don't have spares.

I'm at work so might not be able to reply as frequently as I'd like until tonight but as I've said, any pointers would be greatly appreciated.

ExRayTed · 12 Mar 2013 at 09:42

Did you swap your suspect PSU into your mates rig?

Greeny1994 · 12 Mar 2013 at 10:26

northun_munky said:
To be sure I borrowed a PSU from my mates rig and i still get the same problem.

Sounds like a blown PSU. It could have damaged other components on its way down.

northun_munky · 12 Mar 2013 at 12:50

ExRayTed said:
Did you swap your suspect PSU into your mates rig?

I didn't actually. His rig isn't working (not a psu problem though) but I could try it in my media pc .

JamesTrendall · 12 Mar 2013 at 13:49

this sounds like what happened to me saturday my pc just shut off like the power went no bang no smoke ect...

i used an old psu from a 90's pc and it all spun up fine. test all parts in another pc cpu gpu ram. if they all work there with youur mates psu then im affraid your psu fried part of your mobo as it went out.

northun_munky · 12 Mar 2013 at 19:21

OK, so as an absolute last resort before dismantling the W/C loop and taking the PSU out to test on my other pc i cleared the CMos using the jumpers on the mobo. (I'd already done this using the switch on the back of the Mobo to no avail) I though it was a long shot but I couldn't get my hands on 3rd PSU to test without buying one.

Wierdly, the PC powered on and posted! I checked all the bios settings and the cpu temp was 135c! I'm gessing this might be a fault somewhere as everything was running fine and the pump was on. I loaded up my OC bios settings, restarted checked the temp again which was displaying 19c, much more like it! I plugged back in the HDD and viola, im not back up and running, albeit with my mates G Card.

Is it possible that the CPU ( or the mobo ) has an intermittantly faulty temp sensor? The shutdown temp was set at 85c. Would the pc instantly powerdown or is it a gradual process if that happens.

northun_munky · 12 Mar 2013 at 20:21

Just as a final note, when I swapped my g card back in i was back to square one, no boot and twitching fans...

Looks like it may be the 4850x2.