This is old motherboard with Intel P4 (pin & not pinless) cpu with DDR1 RAM and IDE HDD. I removed all the computer components except powersupply and cpu and try to run it out of cabinet. The powersupply I have is old so brought another powersupply from working pc. I short the green the black (ground) wires to check the powersupply before connecting to motherboard to see if its working before and after connecting to the motherboard. I measured +5v on the power switch header which is available. I short the power switch header with a screwdriver. But the motherboard is not powering up the powersupply and the cpu fans does not rotate. I have clean the motherboard with brush and IP and checked for burnt components or leaky components. I had measured the voltages but I will not get any other voltage except +5v which is standby. Only when the computer starts then only other voltages will be generated. So I doubt the problem is on motherboard restart circuit. Any body have flow chart for dead motherboard or any other pdf documents or give me your own experience if you know the solution...I would be happy to say thankyou. I have multimeter , minisoldering iron hot air soldering station and other tools. Some basic knowledge I have about electronics about components testings like resistors, Mosfet, transistors...