Asteroids PCB issue bad M4 ram even after replacing.
One of my working Asteroids PCBs went bad. A pulsing noise comes through the speakers. Player one start button blinks with this pulse and there are random vector lines being drawn on screen in a diagonal inconsistent pattern. Initially it gave me two high tones and two low tones in test which is confusing since I thought the tones are supposed to stop when it gets to the bad ram. Well I changed R4 and M4. I then got two high tones and one low tone. That would indicate M4 being bad. I replaced it twice no change. I replaced all ram and still no change. I cut pin one at L6 and it went dead. No idea other than its not in the VSM.
One of my working Asteroids PCBs went bad. A pulsing noise comes through the speakers. Player one start button blinks with this pulse and there are random vector lines being drawn on screen in a diagonal inconsistent pattern. Initially it gave me two high tones and two low tones in test which is confusing since I thought the tones are supposed to stop when it gets to the bad ram. Well I changed R4 and M4. I then got two high tones and one low tone. That would indicate M4 being bad. I replaced it twice no change. I replaced all ram and still no change. I cut pin one at L6 and it went dead. No idea other than its not in the VSM.
