non starter

[Baz1]

Just completed a new build. Switch on, fans come on for a couple of seconds and then switch off again. Have fitted a new psu 400 watts just in case.Still does the same thing on for a few seconds then switches off. Ive checked all that I can,and everything seems to be connected fine.
CPU semperon 2800(64 bit). asus
K8N motherboard.
Any other ideas

 

[doolittle]

Oh I remember your post from this (link) thread sorry to leave you hanging but it makes more sense now.

Have you tried the standalone PSU test? That would be a good first step (with both the new / old psu) If the PSU can power on and stay on while disconnected to the mobo / gpu and only connected to hdd/cdrom/case fans, it is probably working correctly. Maybe check voltages if you have a meter handy.

The next step would be to try a bare-bones config with only these connected/installed:
-mobo (not really an option lol)
-psu (plug in ATX / +12v / GPU as usual)
-cpu (and HSF of course, connected to fan header)
-mem (maybe one stick at a time then both in various dimm slots)
-GPU (don't forget the hdd or pcie external PSU power if needed)
-keyboard (need to get to bios in case it works)
-power-on header (from case)
-speaker header (from case)

give the BIOS a jumper-reset, then give it a go. Hopefully the screen will wake up and you are happy

If nothing still, you can remove the memory / gpu / cpu and see if you get the respective beep codes.

 

[Baz1]

Thanks for the tips.Ive tried the first by dissing of the psu and shorting two terinals, the psu fans of at this stage and runs constant.So this proves the psu was ok. Having read an article about the possibilty of the psu not delivering enough amps,I tried the second test with another psu. The motherboard green light is on when it satrts and theres no smell of burning. I shall continue to investigate further, cheers