I've strange problems with my PC for the last 3-4 days. When I try to turn it on, it actually turns on for 1/2 second (fans start spinning and I hear the HDD starting to spin - not at full speed just starting to spin) and then it turns off, on,off without I even touch it. The first thing I've though was it was shorting somewhere so I took it out of the case, placed it over motherboard's papercase and turned it on with screwdriver. It did the same thing. Its very weird because when I take off the AC/DC cable from the PSU and put it back in after 30-40 mins I am able to start the PC with one try sometimes. I personally think it's the PSU not able to spin the HDD at full speed at the beginning of the boot. My PC specs are:
Intel Core 2 Duo E6400
Asrock P5B-DE
2x 512 RAM, 1x 2 GB
HDD 160 GB 7200 RPM
ATI Radeon HD 4670 512 MB DDR3
The power supply is 350W. Sadly, the only extra PSU that I have around is 350W too and it does the absolutely same thing. Anyway, if I unplug the HDD or video or ram the PC starts everytime but ends up with error of the missing part. I explain it myself that the PSU wattage is too low to power up my build. Any advices? Should I change the PSU immediately?