System 11 Alpha Numeric Display Issue

[strongs]

I’ve had what I think is a progressive issue for the last few weeks with my Dr Dude (see photo below)

First I thought it was the ribbon cable as I thought pushing J22 seemed to temporarily repair the issue however today that doesn’t seem to be the case.

So I’ve removed the ribbon cables and power cables for the displays and reseated. But still I have dull garbled displays with a couple of bright spots.

I’m now thinking this could be a component failure? I believe the data cable is pretty new as the last owner mentioned replacing it.

 

[Arv]

Change the 39k resistors at R1 and R4. Might be 48 and 49 depends on the age.

Check your +100 and -100v too

 

[strongs]

Change the 39k resistors at R1 and R4. Might be 48 and 49 depends on the age.

Check your +100 and -100v too[/QUOT

Thanks. How do I go about checking the voltages? Which pins?

Are you saying resistors at locations R1,R4,R48 and R49? Are those all 39k?

 

[Arv]

3J5 Pins 1 and 3 on the power supply board for the +-100v
R1 and R4 on the power supply board
R48 and R49 on the alpha numeric display.

 

[chris b]

Scott you would be just better off sending the boards to jim at my Pinball’s rather than just shotguning what people are telling you to do if you have no idea
If you are not tackled board repairs before you are more likely to more harm than good

 

[strongs]

Pulled J1 and J2 connections and reseated. Fixed issue. Many thanks to @pinballmania