System 11 Plasma Help Pls

[DRD]

The player 2 alpha numeric display on my Space Station has burn issues. It is flakey when cold (the panel flickers, half lights up) but when warmed up it improves and gets to be about 80 per cent right.

Is there a fix for this? Or is the plasma glass itself buggered?

I try to avoid moving and soldering these fragile items if at all possible.

Purely by chance I was able to buy an identical used panel on ebay. The player 3 is completely dead. The player 2 display on this second panel also has a fault !!!!. Of the semi colons ; after each number only the full stop works and the comma beneath it flickers and is about 20 per cent lit. In display test, every comma behaves the same.

Am I right in thinking that as all 7 commas are dead that this means it is likely to be a pcb fault rather than a defective panel?

Any ideas what a fix might be ?

Given that both player 2 panels are faulty on my machine, might the problem be with my actual pinball machone itself - and that the fact that both player 2 displays are flakey is evidence of a problem elsewhere in my machine ?

Sadly I don't have another machine that uses this panel to test in. Banzai has a unique one. My later games are full alphanumeric

I know most folk put in new led units, but I try to keep the old tech going


If I can't fix my existing player 2 I was going to cut off and replace with a better panel from my ebay purchase. But I want to avoid messing about soldering these things if at all possible

Thanks

 

[Epotech]

sounds like its outgassing and so is on its way out. Commas could be pcb or a glass that doesn't have them. LED replacement is getting hard to find.

 

[Sgt GrizZ]

You read through Clays guide yeah ?

PINBALL: Repair Williams System 11 Pinball 1986-1990, part three

hansbalk.home.xs4all.nl

 

[DRD]

No, but will have a look thank you

 

[Jay Walker]

On the one you have pictured, which I take it is the one from fleabay, the player 4 display doesn't look great, either.

Re. the tail section of each comma, it is a separate drive (com) from the dot. Though players 1 and 2 have the same chip, U12, controlling them for both 'envelopes' - players 3 and 4 are similar, where it's called com'. That shared drive for both suggests that the 'new' player 2 envelope is faulty.

 

[DRD]

Thanks for the tips.

I checked out voltages. Cleaned connectors ....

No joy.

So I went old school. Took player one off the ebay purchase. Cut the legs (rather than desoldered). Soldered to my display panel.

Voila. We have lift off.

It's an ugly fix, but I have done this twice on banzai and it seems to work without risking display board damage

 

[M4carp]

I had something like this on my Robocop, I changed a couple of resistors and diodes on the power supply board and it looks as good as new now
Was told to get led displays but I prefer the look of the plasmas, sharper.

 

[DRD]

I think plasmas look so much better. And they have the real nostalgia factor too.

I managed to get a smashed up banzai display board too for scavenging from.