Hello all-
Has anyone successfully replaced the potentiometers on a Gottlieb System 1 power supply? I have a few replacement potentiometers, but they are significantly smaller than the originals, so the leads aren't long enough to reach the holes in the circuit board. I'm sure I can get creative here by soldering lead extensions, but I don't think the end result will be very ascetically appealing. And looks is half the battle, ha! But seriously though, just curious how other people have handled this.

I've spent so much time fixing this board, I'm starting to wish that I would have just bought an aftermarket replacement. But I love to keep things as original as possible...

Thanks,
James

Thanks, I'm not sure why I didn't think to go look there. It's like the board was already designed for the smaller potentiometer - the holes already existed.

So I finished my rebuild last night, and finally put power to the board. Before the rebuild, it would instantly blow the transformer fuse (which now has the extra fuses for further protection). Now, the fuses don't blow, and all of my voltages are good other than the 4 and 5 volts. The 5 volts is 2.3 volts, and 4 volts is ~1 volt. I can clearly see that they are related on the schematic. Turning the 5V potentiometer has no effect on the voltage output. Grrrr.... Mind you I replaced all of the electrolytic caps, every zerer / diode, all transistors, SCRs, voltage regulators and potentiometers (via the kit from Big Daddy). It's been a labor of love, but something still isn't right. If someone has insight on the 5V part, I'd love some pointers. I'm guessing it's related to the LM732, which probably is doing its job, but there's something wrong somewhere. Seems like the potentiometer for the 5V isn't doing its job, possibly there is a solder bridge that I missed on the back of the board. Will check tonight. But again, if anyone is a system 1 PS guru and has advice, I'd love to hear it.

Another fun problem. The ground plane on the game has 10VAC on it. So if I lay my arm on rails, coin door, etc., I get a nice little tickle. One problem after another....

Nope, someone ripped the ground pin out of the cord. Guess that needs to be next on the list to replace.

I did some reading this morning on the power supply and noted that transistor Q1 (big one on the back of chassis) uses the screws to get its power source. Yet, the kit I got from Big Daddy had insulators for the screws. Hmmmm....I put them on. Will remove them tonight to see if that's what's killing my 5V supply, since Q1 ultimately supplies the 5V circuit. =)

I'm happy to report that my power supply is finally fixed. Indeed one of the pots was bad. I replaced both of them with the Cermet pots (thanks barakandl). But the real underlying issue with the 5V section was a bad solder joint on Q1. Ah well, fixed now. I'm so glad that I don't have to take that dreaded power supply apart again!

To my surprise, the game actually boots up. However, it locks up when I try to start a game. I assume the game ROM is bad.

This game has been one thing after another. Lots of years of neglect, hacks, etc. Eventually it will work...

On to the CPU board.

Well I'm fairly sure that the ROM is toast. When I start a game, the little tune sounds, a ball kicks out, and then nothing else works - no switches register and the displays all continue to show 000000.

I can source the ROM adapter, but don't have a eprom burner. Who's best to contact for getting a new 2716 eprom with the Totem code burned onto it?

Thanks!
James

Just a flow up for others with similar problems. Replacing the game rom did the trick. The game is now 100% functional. Amazingly, everything else works short of some bad bulb sockets. And I have the wrong sound rom. I did a lot of board work to this game - glad to see that it was successful.