PC Locking Up

[Lusaris]

OK so new scenario here.

I turn on my PC and its fine. I open WoW or FFXI and play for 15-20 minutes, PC locks up. I reboot and log back into to FFXI or WoW and sometimes it'll let me play for 20mins then freeze or 1hr 20mins then freeze.

My CPU idles at 39C (just added a Coolermaster V8 Heatsink).

I upgraded from an Okia 650w PSU to an Antec 650w PSU (heard Antec was one of the best performers)

The video card that is in the PC now is a Nvidia GeForce 9400 gt. I have tried a GTX280, Radeon HD4650, and a Radeon HD4870 and the problem seems to happen more often with the bigger Video Cards. Its locks up with ALL of these cards.

I dunno what else to do other than to try a new motherboard. Any suggestions?

[Shojin]

Did the problems start when you upgraded your PSU? Try your old one and see if it still happens.

Also, have you checked to see if it is your RAM? That's all I can think of, if nothing else works, then it is probably the motherboard.

Have you run a Diagnostics test?

[Lusaris]

Was having same problem with old PSU. Upgraded due to an issue where the PC was shutting off when i opened WoW due to PSU not supplying sufficient power to the Video Card.

I dont have any extra RAM chips to try. I have 2x Corsair 2gig DIMMs installed and havent had a problem with them to date.

And no, I haven't run a diagnostics test. can you elaborate a little on this? Would like to give it a try.

thanks

[Amarok]

You could try your ram sticks one at a time to see if one of your sticks had gone bad. Aside from that if you're sure it's not the PSU, your processor is running at good temps and you've tried several video cards that kind of narrows it down to mobo or maybe a failing hdd?

Does the locking up occur when you're NOT playing a game and just doing light work/browing the web?

[Lusaris]

During normal day to day activites like browsing or while idle is doesn't lock up, only when i load up a game.

Im thinking about getting a new mobo just in case. I can always return it if needed. but im gonna play with the memory sticks tonight. I did have 2x G.Skill 2gig DIMMs installed but switched to Corsair due to an mem error on boot up when i first got the PC up and running.

It has been running fine for 3 months. My g/f reminded of something that may play a HUGE factor in my issue. The power flashed off the other day and turned off my PC. I rebooted and it seemed fine. About that time is when my on-board ethernet started randomly failing and the the lock ups started.

I haven't ruled out the HDD yet. As my luck goes, the last thing i can possibly replace in the PC will be the fix i was looking for... -_-

[solsirt]

You say your CPU idles at 39C... what about under load? Do you have good airflow? Just guessing, but could the hot air just continually be recirculating in the case?

[Lusaris]

Under heavy loads I peek around 52c. At one point in time i was idle at 64c and peeked 72c under heavy loads. I since then installed a Coolermaster V8 Heatsink (Upgraded from and Intel Heavy Duty heatsink + fan. Which is what I thought the original problem was.

My airflow is decent. I have 2 80mm fans in the front pulling air into the case, 1 80mm fan in the side towards the front pulling in air, 1 80mm at the top of the case pulling hot air out and a 120mm fan in the back pulling hot air out.

[Lusaris]

*Update*

Installed a new mobo: Gigabyte EP45-UD3R and system has been stable playing wow for over and hour. Im going to monitor it for the rest of the night and let it burn in.

I appreciate everyone's help!! thank you!!