3 Replies Latest reply on Dec 27, 2011 11:15 AM by martiantimeslip

    Startup problems on 0N826N motherboard- Dell PC

    martiantimeslip

      Details of my problem below. It has been pasted together from questions and responses on another forum, which did not lead anywhere, so sorry if it doesn't read very smoothly, but all the info is there.Intel System Ident is 0063 4207.

       

      I have a problem when starting my PC when it has been switched off at the mains for a while.Powered on at mains, green LED next to mains plug is on.Push On button, once, twice etc etc no startup.Took off side of minitower case, orange LED on motherboard glowing. No fans active (that is PSU, case , processor).Pushing the On button causes the case fan to give a little twitch (less than one turn), holding the on button down causes the case fan to twitch at second intervals. Tried this several times over the course of a few hours, no startup, finally on one push, processor fan starts and whole thing boots up normally. So some kind of start up problem, but whether its the PSU or the motherboard, I've no idea. I am an EE and have DC probe capability but would appreciate help from anyone who knows how the startup process works on the Dell or indeed any other similar system. Its 2 years old so well out of guarantee. The ON switch is fine, I disconnected it and measured the resistance, its zero when pushed. I can also get the power supply to start up by shorting the PSON wire in the 24 pin power connector to ground all the fans including the processor fan are running,the PSU outputs measure OK, but the processor hasn't booted and the ON switch LED is orange rather than white. That supposedly means the processor is in a sleep state, but it won't come out of that state with keyboard or mouse activity as it should so I don't think that is valid. What I need is someone who knows the circuitry and sequence that follows pushing the ON button, to try and figure out the problem. I've downloaded a motherboard manual but you don't get that much detail.