I have a home pc with an Intel D865GVHZ motherboard and 3.06ghz Pentium CPU (running linux). The system has been working fine until a power outage last week. I wasn't around for the outage. Apparently the power was out for about 10 minutes. All other computers restarted fine when the power came back. 1) When I press power, nothing happens. 2) I disconnected the 20pin connector from the motherboard and connected a power supply tester. The tester indicates the power supply is fine and when I turn on the tester, fans and harddrives that are still plugged in start. 3) When I connect the 20pin connecter to the motherboard, I notice that a small green light lights up on the motherboard. 4) When I press the switch, nothing turns on, not the CPU fan, no other fans, no hard drive, nothing. 5) Thinking that the switch may be bad, I cut the switch wires and touch the wires together and nothing. 6) I looked over the motherboard and don't see signs of any blown resistors or anything. What do I do next? Do CPUs get blown by power problems or is it likely the mother board. TIA Don

could possibly still be the PSU failing under load. the only way you will know for sure is to substitute the psu and cpu (not both at same time) with known good parts

Chances are in your favour that replacing the PS will restore your computer. Those simple power supply testers can only test for the presence of the output voltages, and possibly whether they are within the tolerable 5% or 10% of what they should be. Something else can be and often is wrong with a failing PS that prevents it from booting the computer fully, even if it partially works as your does. Check your PS. See response 4 in this: http://www.computing.net/hardware/w... The green led on the mboard is to remind you that your ATX mboard is always powered in some places as long as AC is being supplied to the computer/it's PS, even when Windows is Shut Down or in Standby or Hibernate modes, or even when you have no hard drive connected at all, and you should always unplug or otherwise remove the AC power to it whenever you fiddle with the components or any connections inside the case. If you don't do that you may damage your mboard or anything connected to it. It is also quite possible the power outage produced a voltage surge or spike that damaged something other then the PS, especially if you do not have everything connected to the computer protected with a surge/spike protection device, including the cable that connects you to the internet. The fact the PS partially works is encouraging however, and replacing the PS may restore your computer no problem. If lightning was involved, even such a protection device may not be enough.

Thanks. It was the power supply. I guess the cheap tester can only tell me that the PS is bad, not that it is good. So can't I just plug in a PS and check that the fan works and get just as 'reliable' results?

"So can't I just plug in a PS and check that the fan works and get just as 'reliable' results?" If you are fortunate, the PS that has failed has not damaged anything else, and trying another PS with enough capacity and that has the same wiring for the main connector will work fine if it is known to work fine with another mboard. If you are not fortunate, plugging in a known good PS won't reveal anything if the original PS damaged something other than itself that causes the computer to not boot - that's often the mboard. Usually if the original PS did not fail completely, then nothing else was damaged, as long as none of the voltages were too high for a while previous, but if it failed completely the chances are much greater something else was damaged.