OP

Quoted from Nihonmasa:

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 => PDB J1/5 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 => PDB J1/21 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 => PDB J1/22 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 => PDB J1/10 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 => PDB J1/3 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 => PDB J1/23 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 => PDB J1/24 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.
[quoted image]

OP

Quoted from Nihonmasa:

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.

OP

Quoted from Nihonmasa:

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

OP

Quoted from Nihonmasa:

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