Sega ST-V Repair Logs
Symptom: RAM failure
Could not duplicate RAM failure message. Game would not boot but system would pass all user tests. Reset NVRAM and system would then recognize cartridge. Set the game cabinet for 2 player mode and took it out of multi mode. System would now see and test cartridge but still fail to play it.
Booted the game into factory diagnostics and ran the factory set of diagnostics on the game board. The board would "pass" the slave CPU but would lock up as that test finished. Pushed down on the slave CPU (Hitachi SH-2 with LOTS of small pins) while booting the board and it immediately fired up the game cart properly. Resoldered the slave CPU and played a couple of games to test the system.
Symptom: Cartridge error
Resoldered the two surface mount SH-2 CPUs, cleaned the slot, and ran the board through diagnostics.
Symptom: Won't play carts
Ran system through self tests. System locked up doing the cart test. Ran factory tests and board passed all except would lock up on testing the slave CPU. Resoldered both SH-2 CPUs and tested.
Symptom: Appears completely dead, yet the LED on the board lights up
Discharged all the capacitors on the board and the board came alive again! Note that the capacitor right next to the LED might take a while to discharge.