PCB Repair Logs Gunforce
Gunforce
 |
|
| Manufacturer | Irem |
|---|---|
| Year | 1991 |
| PCB Image | Reserved |
| Pin Out | Jamma |
Repairer: VectorGlow
Forum Thread: Gunforce PCB Repair
Symptom: On power up, board displays RAM NG 23 and during the game no sprites are visible
Diagnosis: Found that twiddling the jumper JP3 on the top board caused the sprites to briefly appear and disappear, this was caused by corrosion on the jumper. However, the sprites were then corrupted and the wrong colours – piggy-backing a good 6116 on the RAM at IC43 on the top board (this is obviously the ‘23’ as referred to by the self test) caused the sprites to appear whole but the wrong colours.
Cure: Removed corrosion from JP3, replaced 6116 RAM at IC43. Colour problem caused by some mashed and shorted pins on custom at GA22 – pins 160 and down about 4 or 5
Symptom: RAM NG 2 3 4 5 6 and some flickering garbage
Cure: Bad connection on pin 109 on the custom GA23 on the lower board
