I have home built Desk top with Athlon processor & I will Mother board, WD 80G hard drive, It was working very good till last week, I believe, it was on for 4 -5 days & power supply fried & when I replaced with new 400W. It does not display anything on monitor but every things workd fine. When I turn it on again, & went to BIOS , It did not show, IDE hard drive, I opened it check the Power Cable, Check the Hard drive cable both at MB & HD end. Everythings loks good. I tried to restart & now nothing shows on display? Any help would be great.. I have my important data on hard drive.

If nothing displays on the monitor, how do you know everything works fine? You could have damaged the motherboard when the power supply blew, or who knows what else. "When I turn it on again, & went to BIOS , It did not show, IDE hard drive" so do you see any errors during post? What if anything showed on startup, do you get a post screen? any beeps? how many? Read the motherboard manual, it will tell what different beep codes mean.

Obviously if there's no display, everything does NOT work fine. How did you determine that the PSU fried? What were the sysmptoms? Are the same as with the new PSU? Maybe the PSU wasn't the problem. Or maybe it did fry & took out some other components along with it. Or maybe the replacement PSU is a cheapie with poor specs & isn't capable of firing up your system?

Thank you for your response & I forgot to mentioned that it did started everything fine at first & could not find IDE hard drive, Even I could go in to the Bios & set up the Boot preference as Floppy, Hard Drive 0 & CD drive. But now it doen't show up any thing, my understanding is, it could be the Video Display Driver or what? Your help is appreciated. Thanks

"my understanding is, it could be the Video Display Driver or what?" Your understanding is not very good, a driver is software, with nothing working it coudn't be fixed even if it there was a driver problem. Best thing to do is start from the beginning. Remove the motherboard and lay it on the bench on a nonconductive surface, plug in video card one stick of ram, leave everything else disconnected, connect the power, momenterarly bridge the start pins with a small screwdiver to power on and see if it fires up. If it posts ok, turn off and plug in the hard drive and remaing ram if any, see if it recognises the drive. If not disconnect it (turn off power) and try the dvd and floppy. Post back results detailng what you have done, what works and what doesn't, motherboard make and model number