I have Gottlieb System 1 Close Encounters machine. I've been having problems with the game not booting. The score and ball display comes on, but game over light stays on. I also do not hear any clicking of the tilt or game over relays like on typical startup. Upon some further testing, it seems like the driver board is not getting 5v. When I test across C1 cap, I am only getting 0.8V. I get the same reading between the last 2 pins (red and black wire in the attached picture) on the A3-J1 connector. The interesting thing is when I have that connector removed from the driver board, I do get 5.2V across these pins. Has anyone seen this before? Apologies in advance, this is my first time working on a pinball machine

20220120_021322 (resized).jpg

I followed that guide for testing ICs and did some test from Clay's guide (http://www.pinrepair.com/sys1/#testtrans).

I tested all the pins on Z1 to Z9. They were all showing normal readings between around 0.62 to 0.72 (except for pins 1, 9, and 16 on some chips).
I also tested all the transistors. The only one that stood out was Q25. I got 0.63 between the collector and base, but an 'OL' reading between collector and emitter. Is it safe to say this is the issue? It just does not seem like this component is connected to the 5V bus like the other chips.

I summarized all my readings here: https://docs.google.com/spreadsheets/d/1Ca0wSWK5gOS6kstfod-e2SkbAOgYrrr4UXnc4hYhBUk/edit?usp=sharing

Q25 (resized).PNG

So I was reading this thread https://pinside.com/pinball/forum/topic/gottlieb-count-down-losing-solenoid-power-q-relay

I repinned the wires for the 5V and GND going between the CPU and driver boards. The game now boots properly and most things are working.

Whats not working:
1. Hitting the start button on the front panel doesn't kick the ball into the shooter. But if I manually move the outhole kicker, I can play as normal.
2. Score displays intermittently turning off
3. Speaker is constantly on and sounds really loud. I had to unplug it from the sound board, it is too annoying

I figured the first thing to do is just repin everything as the guides say and see what that does resolve. I thought repinning was only necessary for damaged or corroded pins, but I can see the difference now with new pins vs the old in the connector housing.