Hello everyone,

I have been working on restoring a Bally Star Trek. I had it running for about 150 games and now my F4 fuse on the rectifier board assembly module blows immediately on power up. The issue first arose in the middle of a game with my nephew. I tried to reboot the game. The lights all come on, no displays and the game does not run the solenoid test fire or launch the rom.

At first I suspected that perhaps the fuse was just old so I replaced it and tried to boot the game and it gave the same symptoms-lights, no test fire, no displays. I then did a little research around the forum and saw that some F4 fuses would blow with a locked on solenoid. I checked all my connections, put a new fuse in and disconnected all the plugs from the Solenoid Driver board to see if the game would boot without controlling the solenoids to try to suss out if I had one locked on and I had the same no-boot immediate fuse blow.

I am attaching images of my boards. The MPU is brand new due to alkaline damage on the one that came with the machine. All the other boards are original. I noticed there is a little alkaline damage on the Lighting board that I need to clean off but I don't think that is my issue. have done the Vid Recommended Mods to the Solenoid Driver Board and replaced the caps. I have a little electronics experience but just need pushed in the right direction with how to solve this problem.

Thanks- Jackson

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Thanks for your help. I ordered a new one off of Marco's

Okay, I have an update. So i ordered an new bridge rectifier, desoldered the old one and tested it with my multimeter. It was indeed bad as you said. It was shorting from negative to the AC. So i soldered the new one on the opposite side and made sure to solder it on both sides of the PCB as it looked like there were traces on both sides. I popped in a new F4 fuse and put the board back in the game only to blow it again. Thoughts on where to go from here? I tested the new bridge rectifier and it is not shorting.

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Yeah, i lined up the positive with the positive on the pcb and the negative with negative and both AC where in their correct spots. You can see from the picture the other two slots that have the labeling and look at the black imprint on the new bridge to confirm.

The only thing i didn’t do the same was mount it to the back side and there is a screw that goes through the bridge into the metal plate the transformer is mounted on. There is a metal trace were i assume that grounds but i figured the ground would be picked up somewhere else on the board and was not necessary as i have seen other people install new bridge rectifies on the opposite side

Good eye. It is a small strand of hot glue. I put two small scratches in the top trace and used a little hot glue to insulate it just in case it wanted to arc to something else. I will trouble shoot my plugs and report back.

So the worst possible result just occurred. I went through the troubleshooting steps greatwichjohn suggested. I tried just J2-no fuse blow. J2 and J1 - No fuse blow. All three AND NO FUSE BLOW! I have no clue what has changed or where the original issue was.

My thought is that I need to turn the game on, run it for more than 3 minutes, and put some games on it and see if anything happens. I doubt that I had 3 "bad" previous fuses and I double checked and there where all the correct value. If I get it to blow again I will try to diagnose which of the J connectors is the culprit. Feel free to chime in with any theories and thank you all for your help. I will report back if anything bizarre happens again.