possibly replace the IC Z6 on the MPU board see schematic on pages 2 of 3 VII-9 of the service manual gottlieb solid state pinball games 2nd addition. This Ic controls the outhole and as you will see also the knocker, tens, hundreds and thousand chimes.. I had a outhole problem similar to yours, first ball would play but no other ball wold come out to the shooter after that.. this chip is a SN7417N i found them on e - bay. one installed outhole worked fine... Phil USA
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