Williams Honey backbox bulbs twinkled while playing and then went out. The 6V and 24V fuses also blew. Slowly but surely, and I don't know why, the fuses have stopped blowing but the backbox bulbs blow as soon as I press the left flipper to turn on the lights. The transformer seems ok reading 6.7V and 29.8V when measured with the common lug on the 6V and 24V circuit. The rectifier reads .459 and .486 from the pos to AC and the neg to AC. When hooked up to the ground at the on/off switch under the playfield, I read 10V to the playfield lights and when testing the backbox, I get 16.5V. I have attached a pic of the Jones connector in the backbox showing scorch marks.

Any thoughts on the blowing issue? ThanksIMG_20161023_080601898 (resized).jpg

test

When I pull the high voltage fuse (24V) nothing illuminates. When I put it back, it blows along with a bulb when I press the left flipper. Thank you for your interest.

I've suspected that somewhere on that circuit something is touching somewhere. I've traced as much as I can without separating the bundles of wiring, but that may be my next step. I will also move the wiring to the next plug over on the connection.

All righty then, let's take it from the top:With fuses in place and all wires connected, when the left flipper is pressed, there is a large spark in the lock relay where the GY wire from the transformer closes up against a BrY wire that leads to the 6A fuse, which blows.

The brown wire on the other side of the 6A fuse goes to the Jones connector in the back box(among other places). If that connection is broken, the fuses do not blow and the game can be played but without backbox lighting.

Most of the lights in the back box have blown. One of the exceptions is the player up light for #1. I'm out of bulbs now and will have to scavenge off my other machines until I can get more.

It does sound like a 24V line is crossing the Brown wire somewhere and overpowering the lights.

I may end up desoldering a whole bunch of connections to find the point where the two voltages meet unless someone knows a simpler way to track it down.

Again, thanks for your interest and help.

Otaku it seems like you have the correct diagnosis of the problem. With the 24 volt fuse in and the 6 volt fuses out, I read 37 VAC on the load (right) side of the fuses. I read 37 VAC on the upper 6V fuse holder when using the return white wire at the power connection to get the reading. I get 9 VAC on the lower 6V fuse.

I have a Snickers Bar because I don't think I'm going anywhere for a while.

Any advice in trying to track the cross connection?

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I've looked but just cannot find the problem. I tried hooking up my meter for continuity between the higher voltage and the gi lines in the backbox only by disconnecting all wires from the playfield wiring. The shrill sound of the multimeter continued while I wiggled, pulled, pushed and rearranged all the wires in the backbox but didn't get even the slightest interruption. Might as well get another Snicker's Bar.

I have to go to work, but will post pics later. It's not what anybody exactly thought.

Wizardblom gets the prize!! The credit wheel overturned until one of the leaves was bent into the high power. See the picture. This was a tough find.

Thank you all for your help, your interest, and your comments.

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