Had one keep blowing on a Stern Galaxy that turned out to be a bad bridge rectifier. I ended up getting a new rectifier board from Rocketdog. I hear Great Plains Electronics makes a good one too.

Choggard,

Before you just buy a new rectifier board that may not solve your problem. Test all the solenoids on the playfield for shorts. All should be fairly low ohms, but any a complete short than you have a bad coil.

Can also unplug the playfield connector on the rectifier board, power up, and see if fuse blows. If the fuse still blows, bad bridge, if not PF short.

For me, replacing a bridge rectifier is a cheaper better solution than just replacing the entire rectifier board. Would probably take me longer to solder all the wire back to the rectifier board than to replace one bridge.

^Truth. My board had multiple issues (including a bad rectifier) that was just a matter of time before it gave up the ghost. But yes, don't replace your board (or components) until you have at least isolated the issue.

Any chance you can de-solder the power side and then re-test the game. If the fuse no longer blows you've found your issue.

I ment to say of the suspect flipper obviously.

DMM on lowest resistance setting. Measure across the coil lugs. None should be a complete short

Although it's a bit of a pain, being soldered to the board if done well, shouldn't cause a problem as such.

If you have another fuse blowing, can you tell us what circuit that's for.

Also, knowing the game would be good so I can look at the schematics.

Looking at the wiring plan, I have this as a 3A slow blow. Is that what you have there?

It looks like that fuse is the main A/C board feed fuse. Normally the best way to go would be to pull all the plugs from the board and then try them back in one at a time, then turn on the machine to see which plug makes the fuse blow, however your not going to be able to do that given that half of yours are now captive to the board.

Did you check the coil resistances and establish that no one in particular is showing dead short - Zero ohm resistance?

You could also check from the fuse out (with the power unplugged) to the connection posts (J2 - 6 looks to be to the fuse - you want the out), but one of the other pins will be an out from the fuse, which should enable you to see where this leads.

Okay, good luck. Let us know if it sorts it all out.

Choggard,

If you purchase a new rectifier board you will have to rebuild the J3 connector as someone hacked the **** out of it. That drives me crazy....

Need a 20pin connector .156" housing, .156" crimp on pins and i would re crimp the other two connector plugs as well.

Great Plains Electronics if you do not have the parts already.

Also it's ok if your shotgunning the board without having a root cause, but keep in mind thats also probably the hardest board to replace in an 80's Bally/Stern. You have a lot of wires soldered onto it from the transformer, and as Elmer Fudd says,,, Be vewy vewy careful, heheheh.. Take pictures and notes.

Elmer.jpg