So heres the situation. Several days ago I accidentally unplugged the PSU power cord from the wall socket while the computer was in the process of shutting down (after I selected Start>Shutdown), but didn't plug it back in immediately since I was in a rush to leave. The power cord was plugged back in to the wall socket after I got home several hours later. I didn't turn on the computer till the next day. Currently the computer won't boot (no POST) and the monitor displays a warning message that says the computer is going into power saving mode. The computer starts up and the fans are spinning. However, instead of the usual green light that is shown on the front of the tower, a solid amber light appears. The usual loud beep that indicates the POST is not present, and is instead replaced by a very very faint beep that I do not know the origins of (I'm not sure if this was present before). The mouse, keyboard and gfx was removed, no POST. CMOS battery was removed and reinserted and the jumper was reset, no POST (I have not yet tried a new battery replacement). Hard drive and dvd was disconnected, no POST. Power cords and connectors were disconnected and reconnected, no POST. RAM was removed but there was no beeps that usually indicate missing RAM. I don't have another PSU so I didn't try a replacement. The motherboard is a Biostar P4M80-M4, using an Antec SL350 PSU. I couldn't get at the processor since I not to sure of how to remove the heatsink fan, but the model is Intel A80856-003. The system is second hand, so I'm not too sure of it's exact specs. Nothing new (software and hardware) had been recently added. Wondering if anyone has any clue to what went wrong or how I could possibly troubleshoot/fix.