Ok here’s a new one for me. I have a Bally 1977 Evel Knievel SS
Thanks! Ed

Sorry hit send before finishing. I have the entire game working 100%. It has all new Alltek boards (mpu, SDB and lamp driver board). All voltages are correct where they should be. I have 183 v coming to all the red wires on the original Bally displays and 5v coming to the displays too. However I have NO displays at all. The orange dot comes on when the game boots up but displays do not register. The black wire at mpu J1-1 and blue wire at mpu J1-2 both have good connectivity. I re-pinned that entire connector. I check continuity for the mpu connector to the displays. All good.

All fuses have been tested off the boards including the fuse on the SDB. All good. My rectifier is a new Gulf Pinball rectifier. Proper voltages going to the SDB (also re-pinned connector J3 on the SDB).

I’m stumped. What could it be?

Thanks! Ed

I actually just swapped out the Gulf pinball rectifier for a new Xpin rectifier just to be sure. Still no difference.
I’m getting 178.2 VDC at tp2 on the display.

596DD58D-9220-4E8D-931B-1F5594B1944E (resized).jpeg

ED781534-FD22-4290-85FE-56F26AC1EDD2 (resized).jpeg

Quench do you see anything I missed?

Yes I pressed the reset button

I don’t have a logic probe. Is there some way to test with my DMM? Yes I have Wolfpack led displays that I tried with the fuse pulled on the SDB. The led displays DO work but the light output is noticeably dimmer on those displays than it should be. I pulled the led displays from another working Evel Knievel game for testing and they are a lot dimmer than they were in the other EK game.

What should I try next? The peculiar thing is that the Bally displays did work up until a few days ago. And I did remember to put the fuse back in the SDB when I went back to the original Bally displays

@EJS. I just looked up the Alltek board memory reset procedure. It says you set the first switch to zero then all other switches to 1. Power up the game and all logic memory will be cleared in 2 seconds. Then put dip switches back to game settings and boot up.

I have not tried that sequence yet so I will do that today and report back

Thanks.

Ok here are my findings:
Quench I checked voltage on pin 7 of the Bally display chip 4543 on the problem EK game. 1.87VDC

Put that same display in the working EK game
.52 VDC

For reference I checked the 6 digit display on my Bally Skateball game.
.54 VDC on pin #7

Obviously a discrepancy.

BigAl56 I took all 5 of the Wolfpack LED displays from the working EK game and put them all into the problem EK game. All displays worked. Played a 4 player game by hand and all displays scores correctly.
The issue is all 5 displays are noticeably dimmer that they are on the working EK game they came from. I tried connecting just 1 display on player 1 with the others disconnected - same issue. The only thing I notice with the Wolfpack displays in the trouble game is that the 1 and 10 digits are very dim and all the other digits are somewhat brighter (but not nearly bright enough to be normal)

Last thing. I did the Alltek memory wipe procedure and that did not help.

BigAl56 Not sure if voltage matters but I am getting .529 VDC at the orange wire on my display connector that you were referencing. I also checked continuity from A4J1-10 to the display and the orange wire does tone out.

Quench you asked what change did I make? The on,y change I made was re-pin the J3 connector on the SDB just to make sure my power connections were good from the rectifier. I did go through that connector again to make sure all wires are in the correct position and all pins are good and tight

Quench thanks for getting back to me with this info. So I see what you are showing me but which wire positions would I need to change? I did follow the schematic with respect to wire colors. It looks like the schematic I was using IS correct? I have the solid brown wire (60) in pin position 20 and the green/white wire (45) in pin position 17. So it appears I do have the wires in the correct positions?

I will swap MPUs and report back but please let me know if you think I have the A3J3 connector correct as I do have it pinned as per the attached schematic

FBD3021F-A3F1-4755-BDED-1DBBA0A06E53 (resized).png

I’ll check those and get back to you Quench
Thank you

SOLVED! So after suggestions from Quench and BigAl56 I continued to look at the blanking wire and the 2 wires from J3 connector on the SDB. After I re-pinned the J3 connector on SDB, wire 20 was not making consistent contact with the board. This was discovered after re-pinning that wire (again) and making sure the connector was tight.

Thank you everyone. I’m learning a lot lately from you all! Ed