I'll check my notes but I think that is for the 69VAC for displays. Pin 6/7 for the input of the power board. I'll get back to you.

Ya, that happens when someone plays with them and forgets the mica paper and the plastic plugs to isolate tabs from touching ground, for example. I think this is simple but I have to look at my notes.

Excellent advice guys, and I have a good board to take a pic of to show you what I mean about the tab not touching ground. TIP31 at location Q2 is part of the 60VDC conversion so be sure it's isolated as with LIC1 and Q1 (Sure these are fine because if LIC1 was shorted, diodes CR3 and CR4 blow apart, Traces would melt around CR1 and CR2 for Q1). The four diodes at location CR6,7,8,9 make up a full wave rectifier to make the incoming AC to DC. Check those and can be tested on the board to discover a functional short. Crossing my fingers it's simple. Tab.jpgDiode.jpg

System1PowerSupplySchematic.jpg

I can fix you up with a parts list from Digikey, your location is unknown so it's tough to recommend a place. Big Daddy ent is great for USA customers.

A parts list I created you can buy direct from digikey i mean, complete minus resistors

I find Digikey reasonable and I order often enough I don't wait long, I use their "Bill of materials" for williams stuff and others. I don't touch stern units, I just don't like them lol. Like preferring GMC over Ford so I have no good reason to hate them. I bought from Marco ages ago the Gottlieb System 1 Service Manual, it's about 25$ and as well Pinball Resource sells them and they have a very good parts selection for those machines. The schematic I posted I just googled that one for you. Someone put some very helpful information on that. Gottliebs licence holder is real anal about that info being out there so you'll end up purchasing that service manual most likely.

You'll learn little things like disabling slam switches by jumping a cap on the MPU which will alleviate potential headaches down the road. Taking fine paper (I use 1200 Grit) to just clean the stack switches for the Tilt and Game over relays. That cleans things up like flickering GI lighting and other oddball things.

I forgot to mention, that fuse should be a 1/4A fuse for the 69VAC supply. Other then that, I hope you enjoy the experience. Just ask any time I love these old machines