Testing power on a Silverball Mania rectifier board

Gorguy

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Testing power on a Silverball Mania rectifier board

Hi, sort of a newbie question... After replacing a bunch of 44 bulbs with new 47s all my feature lights went dead and I'm trying to diagnose the problem. I'm guessing the BR2 rectifier is cooked.

Does anyone know the proper way to measure DC at the 5 test points on this board? Is there a specific ground point I should be using because the schematics don't mention anything, but I feel like I'm missing something obvious.

This is the board:
AS2518-18
http://stevekulpa.net/pinrepair/as-2518-18a.jpg
 
TIP1, 3, and 5 are your DC outputs. Look at the bridges and put your negative meter lead on the " - " sign terminal. Or just grab any trace on the board that connects them together.
 
Thanks that worked. Almost certain it's bad rectifiers.

On the rectifier board:
TP1(feature lamps) shows almost no power.

TP2(display) looks weak

Other TPs show good voltage.

The only thing I don't understand is that the lamp board is showing perfect voltage at TP2. But I guess that's because it's working but the lamps themselves aren't getting power?
 
Thanks that worked. Almost certain it's bad rectifiers.

On the rectifier board:
TP1(feature lamps) shows almost no power.

TP2(display) looks weak

Other TPs show good voltage.

The only thing I don't understand is that the lamp board is showing perfect voltage at TP2. But I guess that's because it's working but the lamps themselves aren't getting power?

TP2 on the lamp driver is ground. Also, the switched illumination voltage (feature lamps) is not present at the lamp driver board so there's no way to check it there.

Check for AC voltage across the inputs of the bridge you suspect is bad. Then check for DC on the outputs. If you have AC but no DC then the bridge is probably bad.
 
TP2 on the lamp driver is ground. Also, the switched illumination voltage (feature lamps) is not present at the lamp driver board so there's no way to check it there.

Sorry I meant TP1 on the lamp board... Checking with the red probe on TP1, black on TP2(gnd) shows good voltage, but this makes sense because it looks like board gets its power from the solenoid board's +5 regulator.

Thanks for the help guys I've spent the past 2 years slowly refurbishing the entire playfield on this machine(bought cheap from Big Daddy when he was in NV). This is the first time I've really had to dig into the guts of the backbox.

Anyway I've ordered a AN-2518-18 rebuild kit from Big Daddy. Doesn't look to much work to fix.
 
Looking closer I noticed the trace has lifted below the bad rectifier.

Do you guys think this board is salvageable or will soldering in new rectifiers be a waste of time? I haven't checked for continuity yet. I've got a better looking replacement board but it's gonna be a pain to reconnect to the transformer.
board.jpg
 
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That board is definitely salvageable. I would replace those fuse clips while you're at it. A full rebuild is probably the way to go.
 
Looking closer I noticed the trace has lifted below the bad rectifier.

Do you guys think this board is salvageable or will soldering in new rectifiers be a waste of time? I haven't checked for continuity yet. I've got a better looking replacement board but it's gonna be a pain to reconnect to the transformer.

Very salvageable. A little cleaning with alcohol and some TLC and that one should work out fine.
Here is what they look like when they are non-salvageable:
 

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