Bally The Bally Game Show (Bally, 1990) problems

[pmj777jaj]

Any help welcome,This is a new machine for me and I was puzzled by a number of phantom switch operations .After following the switch matrix i found they were all caused by switches in column 5, all saying short.I believe I've traced the fault to the coin door.It has been changed from a three coin door to a single coin door also the slam tilt switch has been removed,
the wiring for the slam tilt and 3 coin door just cut and left loose.What can I do with the loose / disconnected wiring so that the CPU doesn't recognize
these as faults?????. I might be wrong about the coin door but I cannot find any other faults

 

[pinballdaveh]

the coin door switches show as column 1 and should not be the problem. if you tracked the problem to column 5 shorts in the switch tests then Q43 (2n5550 transistor) that controls column 5 is prob. shorted and should be changed as a first step (availible from marco). the loose/cut wire ends on the coin door can be insulated by using electrical tape to keep from accidental shorting.

 

[pmj777jaj]

Thanks for your advice,I can't read my own test sheet, It's row 4 with the faults,
I'll try Q48 and let you know

 

[PinballSales]

How is it? Have you traced the problem and fixed it? Did you apply insulation on the cut/loose wires? Maybe if you could post a picture of your test sheet, someone may be able to figure out what's the problem and give you a better idea on what to do.

 

[pinballdaveh]

Q48 is for column 4 not row 4. is that what you meant to say?

 

[pmj777jaj]

Sorry I meant column 4. Here is a detailed log of the machines diagnostic switch test,
easy spin 25 whi/red short 02 row 2
centre ramp 26 whi/brn short 01 row 1
T in TV 27 whi/brn short 03 row 3
V in TV 28 whi/yel short 04 row 4
T in Trip 29 whi/green short 05 row 5
R in Trip 30 whi/blue short 06 row 6
I in Trip 31 whi/vio short 07 row 1 ????
P in Trip 32 whi/grey short 08 row 8

Further tests show

when switch 28 is operated it also operates switch 60
when switch 29 is operated it also operates switch 61
when switch 30 is operated it also operates switch 62
when switch 31 is operated it also operates switch 63
when switch 32 is operated it also operates switch 64.
All other switch operations appear to be fine
Any help on this one please.

 

[pinballdaveh]

the next 2 chips to check or change are U38 PIA or U40.