Twilight Zone
Bally, 1993I’m pretty sure I have bad caps or a bad bridge rectifier on my TZ power driver board. Changed my fuse in f116 and still get .08v at TP1 so something is wonky.
What’s my best option? Doubt I have the skill set to change the caps/BR. Does DumbAss have a board, use a rotten dog(not sure I want to do that), or does anyone have board repair person recommendations?
First disconnect all 3 connectors : J116, J117 , J118. Measure TP1 again (and or look at LED7, is it lit now?) do you have voltage now (DC Volts, a straight line and a dotted line)?
Measure in AC (wavy line on meter) at J112 between pins 1 and 5 , what do you have ?
Again between J112 pin 1 and both sides of the F116 fuse, what do you have (Still AC)
This unregulated 12V dc doesn't power anything on the board itself, it feeds the Coin door, the Dot matrix controller and the opto boards.
If the voltage reappears when you disconnect J116 ,J117 or J118 then one of these devices is pulling down the voltage.
If you have AC at J112 and the fuse and nothing at TP1 , then possibly the BR5 might be broken , or the filtering capacitor might have issues.
The bridge can easily be tested using a multimeter in it's diode test mode. You'll have to pull out the board to test the bridge pins.
Quoted from Roamin:First disconnect all 3 connectors : J116, J117 , J118. Measure TP1 again (and or look at LED7, is it lit now?) do you have voltage now (DC Volts, a straight line and a dotted line)?
Measure in AC (wavy line on meter) at J112 between pins 1 and 5 , what do you have ?
Again between J112 pin 1 and both sides of the F116 fuse, what do you have (Still AC)
This unregulated 12V dc doesn't power anything on the board itself, it feeds the Coin door, the Dot matrix controller and the opto boards.
If the voltage reappears when you disconnect J116 ,J117 or J118 then one of this device is pulling down the voltage.
If you have AC at J112 and the fuse and nothing at TP1 , then possibly the BR5 might be broken , or the filtering capacitor might have issues.
The bridge can easily be tested using a multimeter in it's diode test mode. You'll have to pull out the board to test the bridge pins.
Thank you for the info! I’ll do that testing today! Definitely the optos as the trough isn’t working and the clock not spinning 
Quoted from Roamin:First disconnect all 3 connectors : J116, J117 , J118. Measure TP1 again (and or look at LED7, is it lit now?) do you have voltage now (DC Volts, a straight line and a dotted line)?
Measure in AC (wavy line on meter) at J112 between pins 1 and 5 , what do you have ?
Again between J112 pin 1 and both sides of the F116 fuse, what do you have (Still AC)
This unregulated 12V dc doesn't power anything on the board itself, it feeds the Coin door, the Dot matrix controller and the opto boards.
If the voltage reappears when you disconnect J116 ,J117 or J118 then one of these devices is pulling down the voltage.
If you have AC at J112 and the fuse and nothing at TP1 , then possibly the BR5 might be broken , or the filtering capacitor might have issues.
The bridge can easily be tested using a multimeter in it's diode test mode. You'll have to pull out the board to test the bridge pins.
So disconnecting 116/117/118 does not restore tp1 power and led 7 stays off.
Testing j112 pins 1 and 5 reads me nothing in V and nothing at the fuse. If I switch to mv on my multimeter I get about 12mv at j112 and nothing at the fuse. I just changed the fuse. I know that’s good. Continuity test on fuse works.
Picture of my multimeter for reference.
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Saint-hyacinthe, QC
Milwaukee, WI