About two weeks ago I restarted my PC, but it didn't switch on. Fans spun for two seconds or so, then everything switched off. After a couple of seconds fans started spinning again, and, again, everything shut down after another couple of seconds. This cycle continued until I forcibly turned it off(with the power supply switch) There was no POST beep code at any time.
Next morning I reseated memory sticks and some connections inside the case, and tried booting with just one memory stick. Everything worked fine from the first try. I shrugged, put the second stick inside, booted and continued working. I often leave PC running over night, so I turned it off only after a few days. Same problem. Since I was about to leave town, I didn't do anything about the problem at the time. A week later, when I returned, I somehow got it working again by reseating everything, but couldn't figure out what was the problem. And finally, yesterday it happened for the third time. I got it working again(again, don't know what I did exactly that helped), but this time I want it gone for good.
Here is what I know about the problem:
- It isn't related to memory, hard drives, graphics card or CD/DVD drive, or at least isn't exclusively related to them:it persists if I try to boot without them(no error beep code when booting, constant reboots every couple of seconds)
- It is probably either related to capacitors, batteries or something that would heat up, though the latter seems unlikely: during the first "boot attempt" after turning the PC on fans spin for longer(3-4 times sometimes) than during later "boot attempts". That could be explained by either something (capacitor, battery) being empty at first and then charging up, with a crash after it is full, or it being full and discharging, with the crash when it is empty. Later "boots" are shorter since it is either almost empty or almost full alredy, respectively.
- it probably isn't related to anything that is used while PC is working, since if the launch goes through, everything seems to work fine.
- I did everything in this checklist, except for checking out PSU since it sounds quite dangerous. http://www.tomshardware.co.uk/faq/id-1893016/post-system-boot-video-output-troubleshooting-checklist.html Nothing solved the problem.
- this build worked with no significant problems for more than a year. GPU, memory, motherboard, CPU, CPU's fan, one case fan and one of the hard drives are one year old. Second hard drive, PSU and second case fan are 3 years old.
- all three times that it booted sucessfully I haven't attempted to boot it for hours before, and I think that problems happened when I tried to boot shortly after another boot attempt, or after turning PC off. Perhaps something(capacitor/battery/something else) that is causing the problem is draining very slowly?
- My build: memory 2x KINGSTON KHX2133C11D3/8GX, GPU Nvidia 660Ti , Proc intel i7 2600K, PSU FSP550-80GLN, Motherboard P8Z77-V PRO, system Windows 7 Pro. I don't know how to find out exact models of everything else, but as I have written before, it shouldn't matter.
So, why is my PC constantly resetting, is something wrong with my PSU and if it is why is it only wrong during launch?