Galaga 3 Repair Logs
The power supply board had 2 problems. First battery on the power supply board had leaked and corroded quite a few components. The second was a blown 3/8 amp slo-blo fuse that someone had replaced with a 7 amp (!!!) fuse that blew as well. Replaced a cracked 10 ohm 5 watt resistor, 1N4001 diode, a shorted 4.7uf tantalum capacitor, and the shorted LM305 voltage regulator. Cleaned the circuit board and replaced the corroded components as well. Set the 5v line to 5.15v and tested the game.
Symptom: Garbled title on the screen
Checked the ROMs and PROMs on the board for proper checksums. Programmed 2 new 82S131/63S241 PROMs to replace 2 PROMs that were for the Gaplus game and not the Galaga3. The title was Galaga3 but the colored outlines were for Gaplus.