On my '84 Gottlieb El Dorado City of Gold, replaced the MPU and Power Supply boards. On occasion, but fairly regularly (every 3rd or 4th game) during play when all the top bank 10 targets hit or the side bank 5 targets hit, they don't reset as they should. When the ball drains they do reset. I looked closely at the wiring, soldering, relay switches, etc. but can't seem to find any issues.
Anyone have any experience with this or make any suggestions as to what can be causing this? Thanks.