Photo: Chris1981

» Forum
» Tech
» Tech: Early solid state
» Bally 6 digit display missing segments on one digit

(Topic ID: 321018)

Bally 6 digit display missing segments on one digit

By Pinash

1 year ago

Topic Stats

10 posts
6 Pinsiders participating
Latest reply 1 year ago by ChrisHibler
No one calls this topic a favorite

You

You are not signed in!

Find in topic

Linked Games

No games have been linked to this topic.

Topic Gallery

View topic image gallery

Screen Shot 2022-08-24 at 1.59.17 PM (resized).png

Screen Shot 2022-08-24 at 1.54.13 PM (resized).png

#1 1 year ago

???

My Lost World credit/ball display is missing segments e,f,g on the 100,000 digit. That specific digit is blocked by the backglass (so it doesn't affect play), but I'd like to fix it anyways. When I swap another display into that location, the same segments are out on the same digit. This only happens on the credit/ball display and none of the others. When I move the display to a different location (i.e., Player 1), it works fine. Since the problem does not follow with the display, my troubleshooting tells me its either the wire connector(s), or the MPU. When I read the theory of operation of how these function, I don't really understand how only a single display location can be effected. Can anyone recommend what else I should check?

#2 1 year ago

RIK

Rikoshay

Pinside member

9y 46,900 1,508

possibly the MC14543/4543 at U1 ?

#3 1 year ago

CHD

Cheddar

GoldenStatePin

Lodi, CA

11y 117K 5,181 17 10

I would think wiring first. The display takes in a set of data the chip decodes to know what segments to light for that current digit. If the decoder was out it would move with the display. I think one or more of the data lines has a bad crimp on that position

#4 1 year ago

DNH

Knxwledge

Pinside member

Ramona, CA

5y 81,300 1,896 11 8 2

Yeah either the MPU connector for the displays, or that specific display connector (seems like the MPU one goes bad more often than the display ones)

#5 1 year ago

MAT

snyper2099

Cincinnati Pinball

16y 103K 7,649

OP
Quoted from Pinash:
When I read the theory of operation of how these function, I don't really understand how only a single display location can be effected.

Because the wires that carry the display data are all "daisy chained". With the game off, use your voltmeter and check for continuity at the e,f,g wires from one display to the next.

#6 1 year ago

???

Pinash

Pinside+ Frequent

5y 72,050 1,040

Quoted from snyper2099:
Because the wires that carry the display data are all "daisy chained". With the game off, use your voltmeter and check for continuity at the e,f,g wires from one display to the next.

My read of the diagrams has the data of all 7 segments carried across only 4 wires (fed to display pins 16-19, and then to the MC14543). I'm not seeing e,f,g wires in the diagram, but none the less I will start a throughout check of pins 16-19 and work my way back to the other displays (and eventually the MPU).

#7 1 year ago

???

Pinash

Pinside+ Frequent

5y 72,050 1,040

Quoted from Knxwledge:
Yeah either the MPU connector for the displays, or that specific display connector (seems like the MPU one goes bad more often than the display ones)

Good data point. I'll replace that that connector tonight.

#8 1 year ago

MAT

snyper2099

Cincinnati Pinball

16y 103K 7,649

OP
Quoted from Pinash:
My read of the diagrams has the data of all 7 segments carried across only 4 wires (fed to display pins 16-19, and then to the MC14543). I'm not seeing e,f,g wires in the diagram, but none the less I will start a throughout check of pins 16-19 and work my way back to the other displays (and eventually the MPU).

That's correct. My fault for suggesting that. You are correct that the segments are on/off according to each display. Those 4 data lines are essentially passing to the display what should happen. If one or more is not connected, it could cause problems with multiple segments.

But, I re-read your original post. How is this even a problem? The "100K digit" is not supposed to even be illuminated at all on your credit/match display... Can you post a picture of what you are trying to fix?
Screen Shot 2022-08-24 at 1.54.13 PM (resized).png
Screen Shot 2022-08-24 at 1.59.17 PM (resized).png

#9 1 year ago

???

Pinash

Pinside+ Frequent

5y 72,050 1,040

Quoted from snyper2099:
But, I re-read your original post. How is this even a problem? The "100K digit" is not supposed to even be illuminated at all on your credit/match display... Can you post a picture of what you are trying to fix?
[quoted image]
[quoted image]

You are right, the 100K digit does not function during gameplay at all, but it DOES illuminate/function during the display diagnostic test though. I try to shoot for 100% functionally when I fix up my games, but I agree it won't affect gameplay.

#10 1 year ago

TOX

ChrisHibler

Chris' Pinball Repair

Chesterfield, MO

12y 120K 9,997 46

That is because it is NOT supposed to light in gameplay. Your machine is working 100%. You may rest now.
—
Chris Hibler - CARGPB #31
Http://chrishiblerpinball.com/contact
http://www.PinWiki.com/ - The new place for pinball repair info

Reply

Wanna join the discussion? Please sign in to reply to this topic.

Hey there! Welcome to Pinside!

Donate to Pinside

Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!

This page was printed from https://pinside.com/pinball/forum/topic/bally-6-digit-display-missing-segments-on-one-digit and we tried optimising it for printing. Some page elements may have been deliberately hidden.

Scan the QR code on the left to jump to the URL this document was printed from.