I did a full restoration on this Gulfstream five years ago. Has played perfectly ever since. In the middle of a game the other night, the playfield and backbox lights all started flashing, and not necessarily in sync. Loud buzzing from all over the machine. I quickly flipped the power off and gave it a rest. Flipped it back on, hit the left flipper button, GI came on, no problems. I hit the start button, game reset then all heck broke loose again, then the 110 fuse blew. I have given the machine a full go over twice, once sober. Have not yet found any loose wires or broken parts anywhere yet. I am going to get into this today. If anyone has any suggestions, I would appreciate it.

I’m going to start with isolating the playfield and backbox first and see what happens.

I have narrowed it down to this 18 pin Jones plug from the playfield. If I leave it out, game reset fine. Once I plug it in, the 110v fuse blows. Now I just have to figure out what these all go to.

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Do you think Im looking in the right direction? I’m going to check these three relays and two reset banks.

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With the slo-blow removed, it does the same thing. Ball count stepper starts to count balls up to 3, loud unusual buzzing on and off as it steps. I kill the power before it goes to end. If I let it go to end, it will blow 110 fuse.

So is it safe to rule out the two reset banks?

Tested, no different.

Also triple checked three suspected relays. 3-in line, special, & coin. All look fine.

This is a little difficult for this reason.
With PF up, I hit the start button, machine resets and then goes black/off, like a slam tilt was activated. Left flipper brings it back to life.
PF up, I hold the ball trough switch closed, emulating a ball in there, I hit the start button, ball count unit starts to count up, loud buzzing between the count up, if I let it finish, it will blow fuse. Happens so fast, hard to see what’s going on with relays. I’ll switch to 5 ball and see if that gives me more time.

Unfortunately, this machine is before service switches were installed.

Just found it, it was not in normal place.

Thank you, I’ll be looking into both of these suggestions tomorrow.

G.. I love you guys and Pinside. It was the bridge rectifier. I replaced it and I am up and playing like new. Thank you Tuukka!!!

@ Tuukka- I used a rectifier from my parts box, but I would like to grab a couple extra for future. Which of these are the correct replacement? The 100v or the 400v?

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