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Bally switch matrix issue

slither

slither

Member
Mar 23, 2013
357
12
18
Portland, Ont.
I have been working on a bally Harlem Globetrotters. All boards were professionally redone. The game is working, but several switches are not, or firing at wrong times. all switches for coils work if tested by momentarily shorting the driver transistor. the ball trough is not ejecting, the drop targets wont reset, the left slingshot is activating the right side, top saucer not ejecting, the ball trough switch fires the right bumper. all scoring works.. Switch test shows #1 flashing. I have re pinned most of the connectors, and yes have rechecked all at least 10 times to ensure correct pin out.. any ideas?
 
T

ToMMy

Member
Dec 18, 2018
32
23
8
Orillia, ON
Manually reset the drop target bank(s), remove the ball from the trough, put the game in diagnostics -> switch test and see if it is showing any numbers (switches) registering or if it flashes "00" (no stuck switches).
 
T

ToMMy

Member
Dec 18, 2018
32
23
8
Orillia, ON
OK. You have a switch or switch diode problem somewhere.
Switch #1 is the top drop target (D) switch, if the drops are up it should open.

If you disconnect connector J2 (top right) from the MPU board and it stops flashing "1" then the problem is on the playfield.
If you disconnect connector J3 (bottom right) from the MPU board and it stops flashing "1" then the problem is in the cabinet.
If you disconnect both J2 & J3 and it's still flashing "1" then you have blown the switch inputs on the MPU by allowing something with voltage touch a switch blade on the playfield.
 
slither

slither

Member
Mar 23, 2013
357
12
18
Portland, Ont.
Ok so resetting targets manually , or unplugging j2 gives me a flashing 0 in switch test...even with targets up and j2 plugged back in, still same issues.
 
T

ToMMy

Member
Dec 18, 2018
32
23
8
Orillia, ON
Therefore you have a shorted switch or shorted switch diode, or if the switches have a small capacitor across them they could be shorted as well.
(under the playfield).
 
R

Rosco

Active Member
Sep 22, 2017
157
57
28
Oakville
I had the same issue with a eight ball deluxe, it was like the game was possessed, I finally replaced ALL the .05 mfd with ceramic capacitors on the target switches and the issue was resolved. I read up the switch capacitors short out on these old games.
 
slither

slither

Member
Mar 23, 2013
357
12
18
Portland, Ont.
Rosco said:
I had the same issue with a eight ball deluxe, it was like the game was possessed, I finally replaced ALL the .05 mfd with ceramic capacitors on the target switches and the issue was resolved. I read up the switch capacitors short out on these old games.
Click to expand...
Thank you...I did cut the caps on the targets...I figured it would help identify the bad ones if any, then replace. No luck...maybe ill try that! Thanks .
 
slither

slither

Member
Mar 23, 2013
357
12
18
Portland, Ont.
Rosco said:
I had the same issue with a eight ball deluxe, it was like the game was possessed, I finally replaced ALL the .05 mfd with ceramic capacitors on the target switches and the issue was resolved. I read up the switch capacitors short out on these old games.
Click to expand...
Do you have a link for the caps you used ?
 
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