Hi All,

I got a Stern trident, not working.
Rectifier board was dead, and wiring was all over the place (see first 2 pics).

Bought a new board, redid the wiring.
Also fitted a new alltek board.

Here is the issue: 5V led is not on on the board, but the over voltage one is.
It only lits up when I plug J4 on the board.

I checked all tensions on the rectifier board: all good
TP1 on the power driver board is at 5V

So I guess there is an issue with my wiring.
I checked the schematics but there are some cables which are absents, and where Ishould have a green one, I have a large gauge Grey...

See pics.

Any help is much appreciated !
20210102_114455 (resized).jpg20210102_114500 (resized).jpg20210127_200606 (resized).jpg20210127_200615 (resized).jpg20210127_200628 (resized).jpg20210127_200636 (resized).jpg

Hi Rik, thanks for the help!

Not sure what you mean but, with J2 only on the Rectifier board, all voltages are good.
But no 5v on the power driver board.

Actually tried to replug everything and no more 5V on the power driver board, so I am wondering if it did not also fail?

ok guys, many thanks for your feedbacks.

I've been working a bit on this, I got a Bally Star Trek tested all boards (MPU and Power driver) => they work just fine.

So the issue is 100% in the cabling.

It seems to be located on the Rectifier board, J3 connector.

What seems awkward to me, according to my findings:

J3/8 goes to Power Driver Board J1/12 According to diagram should be reg +5; what I see written where it is plugged on the new PD board is +13.5 unreg => seems wrong

J3/9 => SDB J3/5 According to diagram should be relay; what I see written where it is plugged on the new PD board is Q15 => seems wrong

J3/13 is fully missing; should be Sol Bus. Where should I pull a wire?

J3/15 => SDB J3/21 According to diagram should be reg +5; what I see written where it is plugged on the new PD board is GND => seems wrong

J3/16 => SDB J3/22 According to diagram should be reg 175 filt. ret; what I see written where it is plugged on the new PD board is GND => seems wrong

J3/17 => SDB J3/10 According to diagram should be reg +5 Filt. ret; what I see written where it is plugged on the new PD board is Trnsfrmr GND => seems wrong

J3/18 => SDB J3/3 According to diagram should be reg 175 filt. ret; what I see written where it is plugged on the new PD board is Trnsfrmr GND => seems ok

J3/19 => SDB J3/23 According to diagram should be Sol ret bus; what I see written where it is plugged on the new PD board is SOL GND => seems ok

J3/20 => SDB J3/24 According to diagram should be reg 175 filt. ret; what I see written where it is plugged on the new PD board is SOL GND => seems ok

Would anyone have a wiring map for the PDB J3 connector?
Below is the image of the connector on the new boards with the info written.
20210131_162004 (resized).jpg

Yep I have those but I don't see the explanation of how it should be on J3 for the SDB

Oups yeah thx, I edited !

So with the 2nd schematics, what are A1, A2, A3 ?
I guess that A2 is the rectifier board ?

So that seems more or less in line with what I found?
But that does not compute with the board I installed.
Aren't Bally & Stern SDBs compatible?

Then where the f*** is my issue coming from?
All boards are testing ok in another machine, except the rectifier which I did not move... Will check this one again, but all tp were ok.

Ok, so I checked everything again, and all seem ok.
The only weird stuff I found was that the +12V outputs 16,2V on the Alltek rectifier board, but the Alltek support says it is normal cause unregulated.
Still lost at sea with this one...

The grey wire on J3 pin1 goes to the backbox GI return as it should, so it's only a color variation on production.

I checked the voltage coming in on J4 of the MPU, apart from the 12V explained above, it's all good.
WTF....

Yep connectors are new, internal break is unlikely as I checked on the pin arriving on the boards and cause the Altek MPU is warning of an overvoltage.
I'll have to once again recheck every single connections going to / from the MPU.

Getting tired with this Trident; first time I have so much troubles with an old Stern.

Yep, that's the plan. Should do it tomorrow if all goes well.

Ok, tried with a different brand rectifier board and a brand new SDB from Alltek => exact same issue.

Will have to spend some time checking all the wiring it seems, wouhou...

On the CPU I have those values: TP1 @ 4,9 V, TP4 @0V, TP6 @ 22V

According to Alltek, their TP are a bit different and my TP4 is for sure at fault:
TP1: +5v IN
TP2: +43VDC
TP3: GND
TP4:: +5V (I have 0)
TP5: VMA
TP6: Zero crossing

Quench: many thanks for chiming in!
Now you have me puzzled; cause I can't see any fuse on the alltek MPU

So, I just tested the ALLtek MPU in a Bally Star Trek => works just fine. TP4 is at 4.9V.

So the issue is unfortunately elsewhere.
I'l ltry to recheck all the wiring going to J4.

Getting tired with this trident... XD

Ok, culprit has been found ! It is the sound board !
When unplugged (the top 2 plugs), the MPU starts and the game works !

Next step: look at the board and probably perform a cap kit