Most times when I attempt to turn on my system it begins to power up for about a second then turns itself off. I then have to turn off the PSU for a few seconds (until the motherboard LED turns off), or it refuses to try again. It can take anywhere from 2 or 3 to ~10 attempts to succeed, and there seems to be nothing I can do to influence it. I've checked that all fans spin up and reset the CMOS, so I can't see it being a motherboard safety feature. I was wondering if it could be related to another problem which ceased at about the time this began: the graphics card fan making a hell of a lot of noise and not spinning properly. It now spins up perfectly, but I was wondering if it could be some dodgy emergency shutdown feature, if such a thing even exists. System spec in sig. Thanks
Is that with your KR7A-133R KT266A? If so it doesn't support any auto safety shut-off stuff so it would seem to definitely point to your PSU. You could try unhooking a few stuff to check, like fan(s), HD/CD/DVD etc. Is it a cheap PSU that came bundled with a cheap unbranded case? Can you monitor voltages at all?
The PSU's very cheap, but voltages appear to be ok. 5v at 4.87, 12v at 11.92. I don't know that this would really explain why it sometimes works and sometimes doesn't, but I'll give your disconnection idea a try. The KR7A-133R does have poweroff on cpu temperature and cpu fan fail, but they're both disabled.
If its an early abit, check the baord for leaking caps. Some of the earlier boards were prone to this as the company used a batch of dodgy caps.
