I recently acquired a new case and PSU (HAF 912 and OCZ ModXStreme Pro 600W respectively). I came back from uni yesterday to move my current desktop innards to the new case (with the new PSU installed) as a temporary measure whilst waiting for Trinity to be released. After a lengthly but largely pain-free instillation, I plugged everything in, depressed the start button and... 0.2 seconds of life. Lights came on, fans span up, and then nothing. Pressing the reset and power buttons had no effect, so I restarted the PSU and tried again, with identical results. Normally these symptoms are fixed every time by simply resetting the CMOS. This didn't work. I've checked the connections and everything appears to be set up correctly. Wierd thing is, the green LED mounted on the motherboard is lit, indicating that power is getting through. It remains on even after the failed boot attempt. Short of switching the PSU to see if the new unit is a dud, what else can I try?
Nope. The thing's an ancient Asus P5B. Despite having it's flaws, it's been a reliable board with nothing breaking over the past six or so years (with the possible exception of the on-board sound, which I never traced the fault to). Update: Tried the old power supply. The only change was that everything flickered into life for a much shorter period. Again, resetting CMOS had no effect.
Try firing it up with the mobo out of the case- sounds rather like the mobo may be shorting out against the mobo tray ( assuming the front panel connectors are all in the correct places- made that mistake myself once but once corrected the pc fires up fine )..
As above, take the guts out or unscrew and place foam under it to prevent the board from touching the case. You didnt by any chance catch a resistor did you in the move? I've done this by mistake before (
Unfortunately I had to leave the desktop behind when I came back. Will try again closer to Christmas.