I have a eMachines T3256. My house's power went off, then came back on the other day. Now, when I turn on the computer, the hard drive light comes on and stays on, the cooling fans work and that's all. The power switch on the front won't even turn it off. I have to unplug it. There is no POST beep or any indication that anything is happening. I've unplugged all cords from back, left the CMOS battery out for several hours, reseated the memory, removed the modem, still nothing. I don't have another CPU to stick in it. How can I tell if it's the CPU or motherboard?????

Could also be the PSU. Even if it is passing some power it might not be the right power.

Anyway there are inexpensive PSU testers.

http://www.google.com/search?sourcei...n&q=psu+tester

Otherwise you would need another CPU to test or try a local computer tech shop (although a new motherboard might be cheaper than that).