Bally Solved Mata Hari (Bally, 1978) Problems

[pater57]

I'm new to working on pinball machines,with that said I have MATA HARI 1978
machine when I turn it on the MPU flashes 7 times,after it goes out, the power-up tune does not play. When I press the self-test button and get to the solenoid test,the #'s 3-4-5 which should be the chime solenoids don't work,instead the thumper bumpers work,and they also work when they are tested as the bumper #'s. Any thoughts???

 

[pinballdaveh]

the mpu sends its solenoid data to j4. 5 data wires send that data to the solenoid driver board j4. that data is then decoded by a decoder chip , then that data is sent to each indiv. driver transistor. if one of these data wires is not working , confusing data will be sent to the decoder chip , which might pick the wrong coils. since mpu boards have corrosion issues the j4 jacks on the mpu are a good place to start