Measure the 5 volts on the CPU board, what do you get?

Too low. Must find out if it is low on the power supply now. Test point at the very top of the power supply marked with a #1. What do you get there?

Too low. You need to look at the 2 connectors at the bottom of the power supply with the round molex pins. See if any are burnt.

That is one of the AC power inputs from the transformer. With the connector plugged back on, and the game turned on. Measure for AC voltage from the grey wire to the grey/white wire. Then measure from the grey/green wire to the grey/white wire. You should have 9.6-10.2 volts AC on each pair of wires.

Change these 2 diodes. Use 1n4007 replacements. Make sure the 2 fuse holders next to the red circle are clean and a tight fit on the fuses, also make sure the fuse ends are clean and not corroded.

Then retest the 5 volts.

ps (resized).jpg

Ok, remove the transistor from the heat sink. Remove the heat sink, remember which goes up. Clean the 2 leads of the transistor with fine steel wool, then clean entire transistor with alcohol to ensure there isn't any steel wool residue. Then take the transistor and insert it into the transistor socket, carefully slide the 2 leads in and out of the socket. This will clean the connection of the socket. Reassemble and retest the output.

I like to see 4.98 - 5.05 volts DC.

Turn on the game and test pin 12 and pin 10 on IC1. You will read DC volts.

This voltage is low. It needs to be @ 27 volts. So either this pin on the molex connector is causing a reduce current flow or one of these 5 components are not 100%.

pasted_image (resized).png

ps (resized).jpg

Check the pins on the square connector in cabinet. Look for loose/ burnt pins, or not fully seated.

pasted_image (resized).png

Oh my!

I believe that would be a 12 pin .093 molex connector. Page 59, connector 7P2/7J2.

If you get out a magnifying glass, you will be able to see the numbers on the connectors.

No stupid questions, maybe some dumb answers thou. If the wires are making a good connection then the wire nuts aren't the issue, but they must have been an issue at one time for someone to cut off the connector. There is only the two connectors to bring transformer power to the bridge rectifier on the power supply and you have replaced the one on the power supply. You are only concerned with the 3 grey wires in the group, these wires bring AC power and a center tap from the transformer to the 2 bridge rectifier fuses and then to the rectifier. The bridge rectifier and the 2 caps and diodes that you just replaced are responsible for the positive/negative 12 volts and the 27 volt control voltage needed to regulate the 5 volts from the unregulated 12 volts. Usually when the control voltage is low it's because of a dried out cap. IC1 can be going bad and dragging drown the control voltage. Doesn't happen very often. Are you able to replace a chip?

Yea that's the kind of photo you get from a cell phone stuck in a coin door. Not the best for sure. They are standard series connectors.

Looking good.
Playball!