Gottlieb SYS80 PSU Components?

[Pauly540]

If you don’t ask, you’ll never know. So I’ll ask. 
Only J1 connected, all inputs correct and Clays mods done.

I have low readings at TPI 1 20v (should be 60v+) and TPI 2 2.3v (should be 42v+). My assumption is that CR5 (1N4759A Zener) showing short on the meter (out of board), is also messing about the 42v section. I’m buggered if I can find a 1N4759A locally (Jaycar, no luck). RS Components stock them, but I don’t want to order a 30cent component online.
Is there an alternative for 62V 1W 5% zenor I can use?

SCR1 ( S107Y1) also seems to be confusing component to locate. Googling alternatives comes back with options T106, T107, C107, SCR101, SCR107, MCR106, but the closest I can find is Jaycar  C106D1 ? I want to replace SCR1, as sometimes I loose my 5V randomly (down to 2V, rectifier hot) and only a power reset brings it back up. I assume this is ‘crowbar’ effect? CR8- IN4734A Zener will be replaced on next shop.
I could send this board off for repair, but I love a challenge, so please be kind to the novice. 
Picture is before mods were done.

[Homepin]

The C106D1 will probably be OK as a replacement BUT the zener MUST be the correct part, no ifs or buts.

[Boots]

I think you can use two zeners in series as long at the sum adds up to the total you require.

[Steevsee]

I've got a spare 62v zener.

Pm me your details and ill post it for you.

[Pauly540]

I think you can use two zeners in series as long at the sum adds up to the total you require.

Are you saying two 1n4752 (33V 1W) might work? Homepin might throw up. Thanks anyway, I think I'll be patient and wait for the correct Zener.

[Homepin]

I think you can use two zeners in series as long at the sum adds up to the total you require.

Are you saying two 1n4752 (33V 1W) might work? Homepin might throw up. Thanks anyway, I think I'll be patient and wait for the correct Zener.

You could use a 39V and a 22V in series (total 61V) but I never recommend it as it is a bodge - especially when the correct part IS available. It would work OK for a test.

Jaycar #'s

ZR-1439 (39V 1W)
ZR-1422 (22V 1W)

[beaky]

I've got a spare 62v zener.

Pm me your details and ill post it for you.

Well done,
I would take him up on the offer if I were you

[Steevsee]

Diode posted.

[Pauly540]

Diode posted.

Thanks Steve, your a champ 

[Pauly540]

Thanks again Steve for the zener. Good use of a cigarette pack for shipping. 

New readings with only J1 connected are:

TP4 5.1V (with pot adjustment) now stable. Jaycar C106D1 (Alternative for S107Y1 SCR1 worked) + I did also replace the CR8 zener IN4734A (Jaycar)
TP5 8.9V. Which is apparently normal.
TP1 (Should be 60V) @ 80.2V 
TP2 (Should be 42V) @ 60.1V 

I was thinking of putting in a resistor on the 60/42V J3 outputs (for testing purpose) to create some load and then check TP1 & TP2 test points, but I've run out of time this week.

Am I now being over critical of these outputs, or have I missed something? I just don't wan't to blow the displays with these high readings.
PS. All cabinet bridge rectifiers and PS (60VAC) diodes were replaced and have a stable 60VAC input at J1.

[Steevsee]

Thanks again Steve for the zener. Good use of a cigarette pack for shipping. 

Hope the graphic images didn't  put you off zeners for life.

[beaky]

Thanks again Steve for the zener. Good use of a cigarette pack for shipping. 

New readings with only J1 connected are:

TP4 5.1V (with pot adjustment) now stable. Jaycar C106D1 (Alternative for S107Y1 SCR1 worked) + I did also replace the CR8 zener IN4734A (Jaycar)
TP5 8.9V. Which is apparently normal.
TP1 (Should be 60V) @ 80.2V 
TP2 (Should be 42V) @ 60.1V 

I was thinking of putting in a resistor on the 60/42V J3 outputs (for testing purpose) to create some load and then check TP1 & TP2 test points, but I've run out of time this week.

Am I now being over critical of these outputs, or have I missed something? I just don't wan't to blow the displays with these high readings.
PS. All cabinet bridge rectifiers and PS (60VAC) diodes were replaced and have a stable 60VAC input at J1.

you probably have a problem with one of the other zener diodes, transistors or capacitors in that part of the power supply.
TP1 should not be that high
the difference between TP1 and TP2 is within tolerance
you can try the following:
check that the resistors are still the correct value (R1 to R5)
replace C1 and C2
Replace Q1 TIP31C Transistor (sub for SW4F013)
Replace Q2 2N5550 Transistor