Bally Power Supply For Commercial Card Rack
I recently had a power supply in one of my Wizard of Wor games blow. It was a pretty spectacular sight really, the capacitor in the below picture glowed for all she was worth. :o)
I've replaced that component and a few more that actually got fried from the fireworks. I also replaced all four 1N4001 diodes since two of them were bad. From the schematics, it looks like the capacitor that fried is part of the circuit that contains the LM317 transistor so I replaced that just for the hell of it.
Well, after plugging in the power supply, the new capacitor popped like a little firecracker. I'm 100% positive it was put in the circuit correctly so it being reversed doesn't explain the problem.
As you can tell, I only know a little about troubleshooting boards. My next step is going to be to desolder all the diodes and transistors and test them one-by-one.
It seems like I did in fact have a brain fart with that capacitor. :o) That still leaves the question of why the two top 1N4001 diodes blew? This is the second time I've had to replace them in the past say 20 hours of play. Luckily this power supply board was picked up for free and can be considered a spare. But still, I'd like to actually get it to work right.