Dig Dug video game by Atari 1982

This repair of a Dig Dug by Atari was all about the power supply.  The symptoms were erratic resets and garbage on the screen. The customer had installed a free-play modification eprom kit (see the pics). The workorder service notes follow:


01/19/2014 09:04:18   Vacuum inside cabinet. Clean/wire brush fuse holders on transformer assembly and tighten connections to big cap and bridge rectifier. Note: this transformer assembly is from a Pole Position, it has a much bigger transformer and was still labeled with a 25 amp fuse for the 5v AC supply, relabeled to 20 amps and changed fuse, also replaced another fuse that was too high. Found bad transistor on Audio/Power board, 2n3055 was leaking base/emitter. Installed new mica and screws nuts on transistor (rusted and falling apart). Cleaned up edge connector on game board. Tested over-night.