I have a Dell D620 which has a particular problem. When the PSU is plugged in there is no indication of charging or any other electrical activity. I have used 3 different PSU's from D620's and the result is the same. The failure was very sudden and as such I suspect that there is a component failure on the motherboard. I have the technical ability to repair it but not the knowledge of the power systems of the motherboard. I have tried searching for a schematic of the D620 but have found nothing so far. I don't want to replace the motherboard due to what could be such a simple problem as I cannot afford it at the moment. Is there anyone out there that could help with this problem?