When working on the power supply, never plug the pcb boards into it. It is a linear power supply, it will work without a load.
It sounds like Q4 is shorted. Remove it. You can leave the other components in.
Check the top pads under the large bridge rectified. When desoldering the old...
Common issue on all Williams power supplies is having the through hole plating not stay with the board when removing the big rectifiers (BR1, IIRC). There is just too much metal between the big copper pads on the top and bottom of the board and the big wires. Most pencil soldering irons can't...
If you replace the linear PS with a switcher, you need to run the ground wire that attached to the PS board to ground to make the door switches work. It is the small connector that also powered the coin door lights.
Clean the contacts on the battery holders and verify that you are getting...
With some versions it depended on the plastic piece that contacted the switches. A square one would be 8 way and a round one would be 4 way (or the other way around). The Chinese Wico knockoffs came with both and a curiously worded instruction sheet explaining which was 4 way and which was 8...
My wife was fine with it until the "Keepers" numbered 27 and I started eyeing the blank wall in the bedroom...:eek:
She is much happier now that I am keeping most of them at The Game Preserve. She still doesn't have all of the living room back (1 pin and 1 slot machine) and the sunroom is...
Two things to try.
1) try soldering the top pads to the leads. The pads are plated through hole so that the top pads are connected to the bottom pads. When removing the big bridge rectifier the through plating often gets torn out with the leads. When this happens you must solder the top pads...
Is this a rev-D motherboard? It will say on the board near the battery holder. Rev-Ds also have the small red inductors near the power connector. If so, check to make sure you didn't break the wire in the -5V inductor. It is real easy to do.
ken
You already have a switching power supply (the black box), but it looks like the original power supply board & heat sink assembly in is there. There are several people here that rebuild those, if you don't feel up to the challenge.
If you are not fairly handy with wiring/soldering I would...
I don't know why this title gets no love. It is a fun machine full of little Python touches (love the ice cream cone on the back glass). People enjoy the heck out of mine.
Anyway, GLWS.
ken
When I had most of my games at home, it was 'The Whole House Arcade', an homage to the Whole Earth Catalog. Now most of them are at The Game Preserve.
ken
You can get the bridge rectifiers from GreatPlainsElectronics.com. GPE carries 3504W (35Amp 400V wire leads). Last time I looked, they still had some of the steel clad ones.
Ed also carries the 18,000 mfd caps to replace the big cap on the board.
When you replace the big bridge...