I recently acquired Close Encounters machine that I am trying to get in working condition again. It sat in a family members basement for many years after it stopped working one day. This is also my first time working on a pinball machine. I've read Clay's guide (http://www.pinrepair.com/sys1/) to understand what needs to be modified on these sys 1 machines. When I received the machine, I went through all the power train testing as described in the guide. Everything checked out:
-coils all had good resistance
-bridge rectifiers were getting good readings
-power supply board was supplying all the right voltages
-displays were working too, but giving me some weird numbers
-startup didn't seem to work either, since the game over and tilt relays did not click

I replaced the C1 cap with 10,000mfd 35V axial cap. At first I thought I would have to remove the board from the L bracket. I started doing so, but realized I could just cut the existing C1 leads and soldered my new cap to them. I also added the ground wire to the negative side of the C1 cap. However, now I am blowing my 69V fuse. It only blows when I have my power supply A2J1 connection and nothing else on the board. With the board disconnected I am getting the following voltages on A2J1:

Pin 1 or 2 to Pin 3 (ground): 12.86VAC
Pin 4 or 5 to Pin 3: 15.56VAC
Pin 6 or 7 to Pin 3: 36VAC
Pin 6 to Pin 7: 77.4VAC

I also checked all the diodes in forward and reverse:
CR1: 0.480 & OL
CR2: 0.553 & OL
CR3: 0.604 & OL
CR4: 0.572 & OL
CR6: 0.583 & 2.668
CR7: 0.596 & 2.684
CR8: 0.587 & 2.683
CR9: 0.576 & 2.687

A little confused why those last 4 diodes are getting non-OL in reverse. Does this mean the diodes need replacing?

Another theory I had was that when I was attempting to remove the power supply from the L-bracket, I messed up the Q2 transistor isolation. Indeed, the mica insulator was shifted and I noticed plastic bolt insulator has gone missing. I adjusted the mica and temporarily removed the bolt until I could get a replacement insulator, but the fuse still blew. Is there anyway to check the transistor to see if it is properly insulated or causing a short?

Any suggestions would be much appreciated. I know I must be missing something silly. Considering if it may be better just to replace with a Rottendog power supply, but was hoping to give it my best shot first.

Bump! I did a bit more testing, based on this drawing: http://www.pinrepair.com/sys1/ps1.gif

I noticed a number of my resistors in the 69VAC circuit appear to be low. These are the readings I was getting with my DMM:

Actual (Expected)
R10: 5.08 (10kOhm)
R11: 5.08 (10kOhm)
R12: 0.987 (1kOhm)
R13: 33.3 (33kOhm)
R14: 6.70 (12kOhm)
R15: 6.28 (10kOhm)
R16: 0.463 (1kOhm)
R17: 2.071 (2.2kOhm)
R18: 9.86 (10kOhm)

If these resistors need to be replaced, what kind of wattage should I use? 1/2 Watt?

I also checked the resistance from A2P1 to A2P3. Any idea if these readings are too low?

Pin 6 to Pin 1 or 3: ~3.3MOhm
Pin 7 to Pin 1 or 3: ~3.1MOhm

I also tested the Q2 transistor on the bottom edge of the board. Assuming the right most pin is the Base, middle is Collector, and left is Emitter, I was getting these readings with the diode test:

Black Red Reading
Emit Collect 0.659
Collect Emit 1.206

Emit Base 0.601
Base Emit 0.837

Collect Base 0.602
Base Collect 2.253

I'm still very new to all this, so any advice would be greatly appreciated.

20210413_225209_resized (resized).jpg

Well, I removed the ground wire from the C1 cap (based on an another thread I read) and also installed some new mica insulators with a new plastic insulators for the bolt. Started it back up and fuse is no longer blowing, but dealing with other issues