I've reverse engineered the power board from a Thinkpad 700C. The P/N is 35G4785, and the FRU number is 48G3712. A very similar or identical board is also present in the Thinkpad 700. The schematic isn't perfect. Open a bug report if you find a mistake. Not all components were identified. A number of parts did not have designators on the silkscreen, so I assigned them new ones starting at 300.

The circuit board has four layers and an aluminum core, presumably for heat dissipation.

Do not fabricate this design. The PCB layout is for reference only. There are ground plane cuts in layer User.9 that need to get transferred to the ground plane. There are minor footprint differences as well. There are still unidentified components in the bill of materials.