wugly
Well-known member
was repairing a seawolf that had the torpedoes firing when I turned the periscope. there was no cross connection with the data lines or inputs for the torpedoes. I did notice the precharge on the inputs was low around 3 volts. I replaced d1 and on the bench the voltage went up to 5 volts. and the game ran video wise perfectly since I had no hookup to test periscope input or sounds and lights. plugged the board in as carefuly as I could. turned it on and d1 let out the magic smoke and the game failed completely. replaced chip on bench and the game was completly dead. replaced cpu and everything seems to work fine again. any ideas why just 2 chips blew up. I want to avoid another mishap on the next try. the game worked before the chip removal and with the second one in it seems to work fione on the bench for start coin up and trigger.