Space Invaders went blank and repeats sound fx

Power…always start with power. Are you using the original linear power supply, and if so, has it ever been serviced?

Are you getting 5 volts if you take a measurement from one of the chips on the game board?

Also, disconnect and reconnect all cables…press on some chips on the game board as a starting point too.

Thanks,
Jason
 
just to add to power problems you require 12 and -5 for the game to work at all. you have chips that use all 3 voltages
 
that game when it comes up and all voltages are present and the clocks are working will automatically display the random data in the rams even if the game is brain dead. it requires the cpu to clear it. a black screen can occur by not having clock signals properly formatted so that data is not being read out of ram and properly format horizontal and vertical signals are not being generated
 
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