Pinball repair question

bradp56

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Ok so I have worked on many arcade machines and have been able to repair them no problem. I have never worked on pinball and a buddy of mine asked me to take a look at his. I am just looking for any common things to look for. The issue he is having is when he turns the game on it will start to blow fuses. Any suggestions to get me started would be very helpful.

Thank you;
 
Check the power supply bridge rectifier(s). There is also the PinWiki page, it has many common failures for many different types of machines broken down by type.

Of course, most pinball machines were assembled with crappy IDC connectors and those just don't hold up over time so you may need to replace some connectors while you are inside the machine.
 
Mata Hari has the power supply in the head, on the bottom right. Bridge rectifiers do sound like the problem here.

-Pat
 
Ok here's what happens as soon as we turn it on the fuse on f6 blows there is a quick light then the fuse blows. This is on the rectifier board.
 
Mata Hari was built in EM and SS, which one do you have?

Very low run in EM, but just want to make sure which one you have.
 
Last edited:
Rectifier Board Fuse Always Blows.
If powering on a game, and the fuse immediately blows, there's a good chance one of the bridge rectifiers is shorted. Try replacing the fuse's associated bridge. Or just do the modification listed above (which replaces the bridges with bigger models).

F1 - BR1 (or on AS2818-49, one or both of the voltage regulators RP1, RP2). Used to power the "switched illumination" (feature lamps).
F2- CR1 to CR4 (four 1N4004 diodes that act like a bridge). Used to power the score displays.
F3 - BR2. Used to power the regulated +5 volts DC.
F4 - BR3 (check varistor on the rectifier board too). Used to power the coils.
F5 - no bridge. Short in the 7.3 volt AC general illumination circut.
F6 - no bridge. Short in the main 110 volt AC power circuit. Check the varistor and the line filter in the cabinet.
 
Did you test the bridge with a meter? No sense in replacing it f it's not the culprit. The consensus here is that's the problem and that is a good bet, but it only takes a minute to test it.
 
When we checked it we were getting readings of either 5-6 or .5-.6 I cant remember is this good or did I do it wrong?
 
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