I'm currently working on getting my power supply board (A2) in order and ran into something a bit suspicious and I'm not quite sure if its normal.

First things first, I checked my transformers and rectifiers and everything seemed good. I ran them by G-P-E (Thanks Ed!) and he agreed.

I just finished installing the following parts to my power supply board (A2):

- TIP31C Transistor (Q1)
- 2N5550 Transistor (Q2)
- 2N6058 Transistor (Q3)
- 1N4004 Diode (CR1-CR4)
- 470uF 100V Axial Electrolytic Capacitor (C1)
- 47uF 100V Axial Electrolytic Capacitor (C2)
- 470uF 10V Radial Electrolytic Capacitor (C4)
- 1N4734A Zener Diode (CR8)
- 1N4738A Zener Diode (CR7)
- 1N4746A Zener Diode (CR6)
- 1N4759A Zener Diode (CR5)
- T10681 (SCR1)
- 500 Ohm Trimmer Pot (POT 1)
- 12K Ohm, 1/2 Watt Resistor (R3)
- 680 Ohm, 1/2 Watt Resistor (R10)

I also made a new fuse panel and replaced the orange cap with a new 6800uf 25V cap.
My 5v stuff appears to rock solid. The 12v coming into power supply board (A2) is a little high, but with some adjustment of the pot, it holds 5v great!

My 42/60v stuff is not so good. Both are about 9v too high! 60v (TP1) is reading 69v and 42v (TP2) is reading 51v. The 60v AC coming in is 64.6v.
I compared some values to the following diagram:
https://images.pinside.com/6/6d/2b/66d2b47753b58a4c2fa0708c62b268670cde5525.jpg

Here were my readings:
E1 76.4v. Mine = 87v
E2 63.6v. Mine = 70v
B of Q2 58.2v. Mine = 64.2v
E of Q1 65.1v. Mine 69v

Note: All of these measurements are under no load.

I seem to gain a ton of voltage after the 4 1N4004 rectifier.

I found this: https://electronics.stackexchange.com/questions/250887/how-to-calculate-voltage-after-rectifier
Which claims "Vdc = Vac * 1.41" during rectification with no load. While the calculation isn't perfectly correct in my situation, it sort of explains why that voltage is higher after rectification. I'm still worried that something isnt quite right.

Does something seem incorrect? Or am I losing my mind and everything is nominal? Hahaha.

Thanks for the help in advance!

Awesome. Really appreciate the explanation! I see what you are saying and have ordered some new 1N4759As! I'll report back with my results! Thanks!

So I replaced CR5 with a new 1N4759A and same result (if anything it was worse, higher voltage). Reading ~72 volts at the cathode of CR5 (E2). I currently have Q3 and the plate off, so I can access the solder side. The CR5 traces and soldering joints look fine to me.

Here are some pics of the board:
a1 (resized).jpg
a1 solder side (resized).jpg

I'm a bit stumped. Could my new 1N4759A be junk?

Bump. Still looking for advice. I went ahead and ordered a 5W 62v zener (1N5372B) for CR5, just as something to try.

I ended up hooking it all up, and with everything under load the display voltages were only 2v over spec and are working great (power wise that is. I have some connector bugs to chase down still). So I'm gonna leave it as is!

Thanks for all the help everyone!