I recently fried my PSU, by assuming as it had eight cable ended sockets that it would support the extra load of a couple of new devices. I wished to replace my CD read only drive for a CD/DVD read/write drive and add a new 120GB Hard drive to the existing 20GB drive. The computer was already fitted with a CD read/write unit which I relegated to a Slave and added the new unit as Master. All functioned well. Then a similar operation was made with the hard drive units with the new120Gb as Master and the old 20GB as Slave. The PSU died after 1 1/2 hours during a data recording session to the new DVD drive. Removing the PSU showed it to be a very basic unit, 200 Watts. This I have since replaced with a new unit again of 200 watts as Dell inform me that they don't make a larger unit for my Dimension 4100. All's well after removing the 120GB H.D. I would like to attempt to repair the duff PSU. 1. Can anyone help me locate Schematic or circuit diagrams for power supply units in general, if possible for a Dell Model PS-5201-7D? I have made a search with hundreds of results but nothing leading to what I really would like. 2. Alternatively where I can find pin outs with functions and voltages for an Intel Corp. Motherboard model D815EEA AAA I0383-202. Fitted with a 20 way dual in line chassis mounted plug and a 6 way chassis mounted plug. 3. Can anyone recommend a direct replacement PSU of higher wattage, say 4OO watts with the same physical dimensions and mounting screw centres for the above board? Or indicate where to look. Thanking you in anticipation of your replies. Oronsay.