Hello, This is my first time here. I hope someone can help me.
I have an e-machines computer running XP home SP2 with an upgraded pci radeon 256 graphics card, fire wire pci and a sony DVD R/W drive.
Original system: T2542 Speaker: SPEAKER, SP-20A MB: MB,IMPERIAL-GV (845GV) MBEM100614IM Chassis: Chassis, Nexgen 2 main chassis frame
CPU Fan Type: Fan,H/S Cel-P4 2.6 462PMouse: Mouse, silver wheel CPU:
CPU,CELERON 2.5G 478P 128K F400 FDD Model: FDD, SFD-321B/LTGNQ
FDEM2097BLCK Video: Video, integrated Power Supply: PS, 250 watt Modem: Modem,Conexant, fax/modem v.92 56K LAN: LAN, 10/100 integrated HDD: HDD, 40GB 5400rpm WD Keyboard Model: K/B:KB-9908,EN104K,PS/2,EMA,C-blk/slvr ODD1: 48X CDRW (48X24X48) Memory:
Mem, DDR-RAM 256MB (Max. 2GB)
Everything worked fine for the last year and a half or so since the upgrades.

Ok, So this is what happened. Four days ago my wife said we had a brown out or two so she turned off the computer at the switchboard. When she turned the computer back on later the computer started up like normal with the blank screen then the windows dots running left to right then the choose user screen. This is when it froze. The mouse did not turn on (MS wheel mouse Optical with red light) no light and no keyboard. Could not restart in safe mode or from boot disk because the PS/2 keyboard was dead. Would not load at start-up I guess. It would do this every time you tried to start it.
Press the button on the front and it would seem to shut down but the little green light around the button would stay on. Turn it back on same thing.

So I unplugged everything took it downstairs opened the side panel and blew out all the dust with a computer air duster. It looked "OK" inside and I did not at any time smell any hot or burning circuits. So I plugged it back in and the same thing happened. I looked inside and both fans were working but when you turned it off it did not seem to shutdown all the way, the light would stay on around the button in the front. Oh, I forgot to mention the hard-drive light would flicker a little when it was on.

What I did next may have been a mistake, I don't know?
I unplugged the computer and removed the motherboard battery for thirty minutes. Then I replaced it and turned it back on, it started back up but I did not have the monitor downstairs so I turned it off and it sounded like it really shut down this time. So I hit the button again and nothing. Dead PC.
The only thing else I can tell you are that the little green light around the push button on the front of the computer is still on and there is a tiny buzz from the power supply.

Any ideas,
Drewru

Welcome to the forums,

Unfortunately with any type of un-planned power loss you stand a big chance of damaging any one of a number of components inside your PC. Try stripping the PC back to the absolute basics, CPU, RAM graphics card and hard drive only. Does it boot?

Power supplies go out quite often even on new PC's.
Try replacing the power supply you can get them at a decent price on CensusPC.com.