This is one Phantom of the Opera without display.
I bought one Williams display from Rollergames.
When i put it in POTO the display show the inverted signs. ("YOUR...")
YOUR___.jpg

Remarks:
The POTO MPU is original condition and not soldered.
This Rollergames display works perfectly in my Bk2000 too.
I would like show the pics about the segment test:
Segment_test2.jpg
My opinion: the PIA (8-9B) is give the inverted segment signs to display board via data cable (CN22)...
Possible to change on the MPU board outgoing sign polarity with some jumper remove or install?
Did somebody experience about it?

Thanks in advance...
Greetings, SOKOL

Yes, the Williams display is not compatible in the Data East game.
But i don't understand why changed it the Data East company.

I need to replace some integrated circuits on the board...
Thanks.

Thanks snyper2099!

Me too. I many times replaced and used in oldest type (TM, SS, LW) DE pins the Williams display and i haven't was "incompatibilities" problem.
The DOT displays type (LV3, SW) also same as Williams...possible to replace too.
EXCEPT THIS TYPE with 2 x 16 displays.
WHY??

I checked the ribbon cables and changed it in Bk2000 too.
I'm sure, the Williams display board and the cables is OK.
I just have a try at spare my work if possible to remove or install the jumper(s).

Thanks zaza! )
Now i see what will show me the POTO when will be well.

I have a request from you...
It possible the BTTF display is same as POTO display board.
Could you upload here one pic under the ribbon cable (CN5) connection?
I would like to see what type of Integrated Circuits U6, U7 and U8 has in your BTTF display board.
Thanks in advance...

Thanks for everybody the display is already working well.
Greetings, SOKOL