I recently brought home a dead Gottlieb Close Encounters that was in storage a long time.
The battery was not removed and I was not fortunate enough, so the control board needed alot of attention
to replace a few parts and repair a load of traces.
But with this done, it powered right up, and all the coils and lamps work.

But the capacitors C1 en C6 on the power board were dried out and leaking so i decided to replace them all.
C1 4700uF 35v
C3 470uF 10v
C4 1000uF 35v
C5 47uF 63v
C6 220uF 160v
C8 10uF 160v

After this I measured the outputs. +5V and -12v for the cpu were ok. 60v and 42v for the displays also
but the 4 and 8v reference for the displays were way to high. 12 to 14v

Now i have replaced Cr21 with a new 8.2v zenerdiode and Cr22 en cr23 with new 4148 switching diodes.

Now the +8v is there but i've lost my 5v output getting only 3.4v and the 4v output is only 2.1v

Any advice on where to look to repair the 5v output?
Also the place for resistor R1A is not occupied, but mentioned in the schematics.
But looking on google and ebay for other references. it is missing on others aswel.
so i guess it is not needed?

Thanks to any that can help me debug this problem.
I added an image with the voltages i measured on the 723 regulator ic

TenaciousT, nahh now whats the fun in that
The best reward is to see the thing working again after some tinkering.

System1psu (resized).jpg

Resistor R1b i have 0.6ohm so its just a moved R1a then.
Thanks for the info CactusJack.

G-P-E
grounds for +5 -12 +4 and +8v were taken from connector j2
ground for 60 and 42v taken from connector j3

measurements on the ic also from j2 since its part of the 5v circuit

Thanks for the suggestions CactusJack
I removed the thyristor reflowed the solder around the throughhole ringlets.
Put back together. 5v not yet restored.
Collector (screws) of Q1 has connectivity to pins 7 and 8 of the 723 regulator
Base connects to pin 6 of Q1
Emittor connects to resistor R1B

Pot full open measures 1kohm but doesnt seem to influence the voltage.

edit
Problem seemed to have been a dirty potmeter.
Cleaned it with contact cleaner, full down 0 ohm, up 1kohm
But now my 5v voltage is a bit high. Pot all closed (no load) i get 7.1v turn all the way up 10.4v
Turned all the way down, with load of mpu I measure 5.8v over C16 on the mpu.
The mpu starts up normally and a game can be started.
But is this within accepted range? or how can I lower it still?