Computer turned off during a game, now it won't start again.

[Sirregular]

Hello,
Starting this morning, while playing Final Fantasy XI, my monitor went black and said 'power saving mode' while the game music continued to play. A moment later, the computer shut off completely. I rebooted and started the game again, ~10 minutes later, it shut down again and I started to suspect this was a more serious issue.
I turned the computer back on and did NOT turn on the game, however the computer continued with this behavior.
 I assumed this was an overheating issue so I searched around with the laptop and found a program called everest, turned the computer back on, downloaded it and ran it quickly before my computer turned off again. I looked around for a temperate gauge for my computer but it doesn't appear to be running high. However I could be wrong.

I opened the case and blew all the dust out of it, it's mostly clean. After multiple attempts, the computer now doesn't even boot up before it turns off again, so I suspect it's a power issue.

This is my computer.

http://www.newegg.co...ntent-_-text-_-

The only difference being I replaced the video card with Nvidia 9800 GT several weeks ago. Could this have killed it somehow? It was running great until just this morning.



Thanks

[2x3i5x]

please fix your newegg link. It does not work as is because you linked it to www.newegg.co which isn't the right site.

[Sirregular]

http://www.newegg.com/Product/Product.aspx?Item=N82E16883227131&nm_mc=TEMC-RMA-Approvel&cm_mmc=TEMC-RMA-Approvel-_-Content-_-text-_-

For an update, my computer now only runs for several seconds and won't boot up fully before powering off, leading me to believe it is  power supply issue...but I am still very unsure

[jason2074]

Try opening your CPU casing(side or both) while booting. If you suspect the PSU, then remove optical(cd) drive/s(if CPU came with it) power connector and leave hard drive alone while booting to unload power shortage distribution. Make sure also that PSU fan is not dusted for efficient performance. Try posting exact temperature. If you dont have Hardware Temperature Monitor, please download one.

[JJ 3000]

Do you still have the old video card? If so, try swapping it in there to see if the problem persists.