Moving this thread to the proper forum.

GTB Raven. Game boots partially: playfield feature lights come on and go into attract mode. Displays do not come on, game will not accept credits and will not start a game. Must an 80b have a battery in or connected to the CPU to fully boot? Any other suggestions?

After a couple of suggestions from other kind Pinsiders, here's an update: ground modes done at transformer, all boards grounded, fuses good, slam switch mod done.

Checked voltage at display connector A4J1. Pins 1 and 2 (6.2 VAC & return) shows voltage jumping from .3 to 25.5, changing constantly. Pins 3 and 4 (32VAC & return) show 21.6v and 19.7v respectively. Tracing back to A10P2 gives same readings.

I just remembered that some moron cut the ground prong from the wall plug. Could that have any affect? Going to replace the plug.

OK, this POS just regressed. I go to power up this morning and, nothing. Bupkis. No lights, rotor, LED, nothing. Fuses F8 and F20 were good, but replaced anyway. Connector J12P7/J7 on transformer firmly attached. Installed new 3 prong plug on line cord. Utility socket works.
On/Off switch gone bad?

Hey Topher, I appreciate the tip, but I have no AC voltage going into the three bridges, much less any DC voltage coming out. I don't have any voltage at any of the lugs on the transformer. I'm going to go over the schems and do some testing with my DMM.

I've been looking for lost voltage, but is it possible that the conditions described above could be caused by a lost ground?

Thanks again, Topher, but as you can see, I already checked F8 & F20.

Finally found the problem. I unbolted the transformer from the bottom panel and flipped it over. That way I was able to test continuity with the fuses in the F8 and F7 fuses. F7 showed good but F8 showed no contact. The cap that holds the F8 fuse in has these tiny lugs on the inside that make contact with the fuse holder. They were broken off or bent back and just fell off when I tried to unbend them.

I'm going to label the five wires under the transformer, cut them off and remove the the old fuse holders, run the wires up through their holes and install regular inline fuse holders like F1 through F6.

I'll let you know how it works out.