Bally Eight Ball Deluxe (Bally, 1981) help troubleshooting

[larry_67]

Need some assistance troubleshooting an 8 ball deluxe game, the MPU board looks to be in good order no corrosion. ( lucky because it still has the original battery.) The sound board has an LED, blinks once on boot and then 3 times a pause and 1 more time. There is a hum that comes from the speaker but and some of the board lights come on. all removable fuses are good (F 4 ) is missing. not sure what that controls, I bought this as a project not working, I was told that F4 was not needed to function.
Any help would be appreciated.
Thanks
Larry

 

[pinballdaveh]

the F4 fuse is for the solenoids and is a 5 amp fast blo. its missing because there is prob. a bad coil somewhere and it is needed to operate correctly. does the MPU board LED blink a total of 7 times(1 blink a pause then 6 more) on power up? inspect coils for burnt coil wrappers and smell. burnt coils will blow fuses and sometimes take out its driver transistor on the driver board.