When I power up the computer, the processor fan comes on but nothing else happens. I thought that the motherboard and/or processor had went out. I purchased an upgrade kit which came with motherboard (K8M-800M), processor & heatsink (AMD64 3800+ Socket AM2), and a new power supply. I was told that the old RAM (256 MB DDR) would work on the new board, so I just moved the RAM over. After installing the the new parts, I attempted to reinstall the OS and drivers. However, the same problem occurred. Only the fan would start and nothing else - the CD drive wont even open. So I figured the only thing left would be the hard drive. I installed a new Maxtor UATA 100 - 160 GB hard drive. Now, I have a new motherboard, processor & heatsink, power supply, and hard drive; however, I still have the same problem - only the processor fan will turn on. I have checked and double checked to make sure all cables are properly connected. Everything appears to be setup properly. Is there something I am missing here? Any suggestions would be greatly appreciated.

Sounds like your PSU (power supply) went out.

Yes it sounds like your power supply shorted out your old board and when you replaced the board again with the old power supply it shorted that one out as well. Rule of thumb: Emachine power supplies are garbage always replace before installing new hardware --even a new video card

Bench test the motherboards and power supply.

When I installed the new hardware, I also installed a new power supply unit. I don't mean to sound dumb but how do I bench test the motherboards and power supply?

Don't ever waist money on an E machine again.

To bench test: Remove the motherboard from the box Place it on an insulator Connect the speaker cable Connect the monitor Hook up the power supply Either connect the power switch or short the power switch terminals