Bally Eight Ball (Bally, 1977) Need help

[spag256]

When I perform a solenoid test on my eightball pin the Outhole kicker,Side return kicker,Left,Right and bottom thumper bumpers,left and right slingshot and the coin lockout door solenoids don't respond. Only the Knocker,Chimes and flippers respond. I purchased a new solenoid driver module and the same solenoids don't respond. What can I do?

 

[pinballdaveh]

there is a data loss between the mpu and sol. driver boards. with machine turned off remove female plug J4 on mpu(lower left 19 pin) and female plug J4 on sol. driver (lower right 12 pin). using 2 small sewing needles and dmm , stick needles into female holes to resistance check connectors and wiring. data lines on mpu jack J4 are pins 1-8 and 10, and sol. driver jack J4 are pins 3-11. repair or replace any bad connections. if all wiring tests fine the problem is prob. on mpu board. if board ever had any battery acid damage male pins on J4 may be bad , acid got into female connector J4 may have corroded connections. the next thing to check is U11(6820 PIA chip now replaced by 6821, lowest 40 pin socketed chip on mpu board) for acid damage , weak socket , or 6820 needs to be replaced. new 6821 chips are availible from marco pinball or maybee pb resource

 

[Itchigo]

I fixed a lot of chips by gently lifting them up (micro screwdriver), and pushing them back in (thumb). You will hear a "crinckle" sound when you do. I solved many service calls that way.