Biostar TA785GE not booting?

[Tonga000]

Hi all,

I just installed a new 550W PSU after the old one stopped working, but now my PC won't boot. If I plug it in and press the power button, a few LED indicators on the motherboard turn on, and half a second later turn off. Then the power button ceases to have an effect; this only happens after unplugging and replugging. The lower indicator lights say everything is normal, and the upper first indicate all phases active, then the second, and then turn off. Could anyone help me?

Thanks in advance!

 

[rolli59]

You hooked up both 24pin and CPU power to the board?

 

[rolli59]

Then it is time to reseat everything like ram and such.

 

[Tonga000]

Yup, both.

 

[Tonga000]

Just got back from a trip... I've just finished trying that, but no dice. My guess is that the motherboard's dead, but before replacing it, is there anything else I can try?