Bizarre power on issue - help appreciated!
I was recently tinkering with my system and when it came to pressing the power on button nothing happened. I opened up the case and the green light on the mobo was on so I knew power was getting there. I assumed it was a power switch issue so I shorted out the power switch pins on the mobo and all was well.
More recently I am getting the same problem but now shorting out the switch doesn't work. One morning she refused to power up so I laid it on its side, opened it up, pressed the switch a few times and swore at it. Nothing happened. SO I am just sitting there conjuring up new swear words when it just starts up, fans spinning and away we go - I never even touched it. I have restarted a number of times today and no problem. I'm afraid to power off for an extended time, but I live in Houston and this puppy puts out a fair amount of heat and we don't need any more heat in the house! This pattern now happens every day. I shut it down at night and then the next day it will not start unless I lay it on its side and start to disassemble the case and then it starts with no button pressing!
So it doesnt seem to me that it could be a PSU problem? While running, voltages are stable etc. So is it a mobo problem? It seems after an extended shutdown (i.e. overnight) it cools down (?) and then won't start. Is that a symptom of something cracked? A grounding problem? How does it fix itself and then start without pressing the button?
I don't mind replacing parts - I just don't know which parts or how to troubleshoot this problem.