Hmm I thought I posted this last night, but it doesn't seem to have shown up 15 hours later. Here is what happened. A few days ago i bought a new video card to upgrade my system. I installed it, and i was able to start up just fine. I installed new drivers and then shut down. I then reconnected some power wires to make it neater and then the computer wouldn't start. The fans wouldn't spin and the computer wouldn't beep or POST or anything. So i put the wires back the way they were and same thing. However if i turned off the power supply from the back and turned it back on and then pressed the power button, the fans would spin for half a second. After giving up i came back a few hours later and all of a sudden it started up just fine. I was able to shut down and start back up just fine too. Then yesterday i was installing a new harddrive. When i went to turn on the computer, the computer wouldn't start. However, this time the fans would spin, but the POST LED wouldn't light up, and there were no beeps. I then reset the CMOS and still same thing. Then a little while later it started up all of a sudden. It took me to a screen that said 'CMOS failed checksum, defaults loaded' and gave me the options of F1 to continue or DEL to enter the BIOS, but it wouldn't respond to my keyboard. The LED lights on my keyboard lit up however. Anyways i decided to try and flash the BIOS so i shut it down and connected a floppy drive, but now it won't start up again. I'm back to the fans spinning, but no POST. Also when it went to the CMOS failed checksum screen it listed all the memory as ok, and i checked the voltages and temperatures and they were all normal. Ive gone through and made sure my RAM is seated firmly, the video card is seated, all the connecters are firmly connected, etc. Any ideas what is wrong, any help would be greatly appreciated? Here are my comp stats Enhance Electronics 350w PSU Epox 4SDA5+ mobo 3 x 256 MB PC2100 RAM (Kingston, Crucial and Samsung) Pentium 4 2.53 ghz CPU Connect3D X800 XT 256 mb (AGP 8x) 1 x DVD Drive 1 x Sony CD-RW drive 1 x Seagate 40 mb 5,200rpm ATA100 harddrive 1 x Seagate 80 mb 7,200rpm ATA100 harddrive (new)

Will the system work if you put the old video card back in??? If it will, then your power supply is lacking the juice to run your system with the newer vid card. Even tho a PSu says it is rated @ 350W, it may not be able to supply that. Don't ask me why - ratings are usually at max power, not sustainable load. Some tested don't come anywhere near what the ratings say. Not sure where you live, but you can go to newegg.com to get an idea - Rule #1: Good Computers don't go down. Rule #2: There is no such thing as a good computer.

No i don't think the PSU is the problem. I went to a power usage calculator from extremeoverclocking.com i think and it said i only needed like a 300 W power supply with CPU & video card at peak usage. Also I was able to play Battlefield 2 with my new card installed with no problems.

Wattage calculators are just that...wattage calculators - they don't take amperage into account And why would you install a new HDD in a PC that won't even post? Gut the system & see if it will boot with minimal hardware...& make sure your video card is connected to the PSU. ASUS A7N8X-X Athlon XP 1800+ 8.5 x 200MHz 1024MB PC3200 2.5-3-3-7 Asus A9550GE/TD 128MB WinME/WinXP Pro SP1