Hi, I am trying to fix my nephew's PC. The Asus A8N-SL1 Deluxe mother board shows a green power led but it will not power up. The power switch does short the power up pins on the motherboard also I disconnected the PSU lines and pulled the power up pin of the ATX 24 pin connector to ground and the PSU powered up and provided +5 and +12V. I have removed the battery, performed the real time clock reset process as per handbook and put in a new battery. Still no luck and I am at the end of my knowledge. Can anyone give me some idea of the hardware function of the mother board during power up please? Is there a simple hardware latch somewhere or is there some sneaky LSI device involved? I would be grateful for any suggestions.
generally soon as you hit the power switch pins on the motherboard either shorting them using the power switch or using a screw driver that sends the signal to the power supply unit to turn on (from standby mode). you could try re-seating cpu,ram, graphics card to make sure nothings shorting, even test the motherboard outside of the case. you could also try another power supply unit. Other than that your looking at a faulty motherboard sounds like it could be mosfet voltage regulators.
Hi Bob Thanks for the ideas. I haven't been able to find out how the motherboard handles the power up signal so I will do as you say and play with the motherboard and cards. First I will try to find someone with a Sata HDD interface and back up the hard drive. If I get it working I will leave a post. Thanks.
