(Topic ID: 186967)

System 11 B Display Problems - send help!

By fusion301

4 years ago


Topic Heartbeat

Topic Stats

  • 28 posts
  • 5 Pinsiders participating
  • Latest reply 3 years ago by FiatsRUs
  • Topic is favorited by 4 Pinsiders

You

Linked Games

No games have been linked to this topic.

    Topic Gallery

    View topic image gallery

    IMG_0214 (resized).JPG
    IMG_0213 (resized).JPG
    IMG_0212 (resized).JPG
    display (resized).jpg
    IMG_3584 (resized).JPG
    IMG_3581 (resized).jpg

    #1 4 years ago

    Hi everyone working on getting a dead as a door nail police force back up and running - it had some battery damage and wasn't booting, I resolved that issue with replacing a few IC chips and cleaning up the damage.

    The displays were not working at all which I traced back to the -100V circuit where there was a bad resister (R4 I think it was) Anyway now I got the voltage correct, this is what I get (top main display works almost perfect) bottom main display has middle segments and left bottom and bottom out, and the small jackpot display at the top does not work at all. My question before I start testing every chip etc on the display board is could this be something with the CPU board since thats where my other problems started and if so where should I start investigating?

    IMG_3581 (resized).jpg

    #2 4 years ago
    Quoted from fusion301:

    could this be something with the CPU board

    Yes.

    Quoted from fusion301:where should I start

    Buy a logic probe. Check the SRC packs for low pulses for the missing segments.

    #3 4 years ago

    Thanks Logic Probe added to my amazon cart

    #4 4 years ago

    Let me know when you get it and start troubleshooting.

    #5 4 years ago

    Got the logic probe, started messing around with the little knowledge I have - haven't found anything too obvious on the CPU board. Can you point me in a direction - keep in mind this is my first time trouble shooting with a logic probe.

    #6 4 years ago
    Quoted from fusion301:

    Can you point me in a direction - keep in mind this is my first time trouble shooting with a logic probe.

    Logic probes make troubleshooting real easy. In your pic the bottom display looks like its missing segment C and D. So lets start with segment D. On page 88 of the manual it shows the display board component layout. So start at display 2 D segment, it goes thru U-19 and then thru U-11 and then to J-5 pin 5. This is a blue/green wire and goes the CPU J-3 pin 5. Put your game in display test and lock it on a number that uses the D segment on the bottom display like 2,3,5,6 or 8. Now check for low pulses at J-3 pin 5. If you have low pulses at the cpu then your problem is on the display board.

    #7 4 years ago

    OK, so I locked the number onto number 8 so both C and D should be on - tested J-3 pin 5 and 7 (segments that are out) on the CPU board and my probe just goes to HI, the other pins are all pulsing on that connector. Im starting to think there is something wrong with U51 on the CPU board, I have already changed U41 and U42 (am I on the right track here?)

    BTW Thanks so much for taking the time to help - hopefully this also helps other people with similar display/battery damage issues

    #8 4 years ago
    Quoted from fusion301:

    Im starting to think there is something wrong with U51 on the CPU board

    If they were stuck low, then it would be pull up resistors. Since they are stuck high, this is a Pia chip (U-51) or a broken traces on the board from the corrosion. I would retest, but this time check for low pulses on the pins of the Pia chip. This will tell you what you have left to do.

    #9 4 years ago

    Great information, thanks I will replace that chip after testing again and let you know the outcome.

    #10 4 years ago

    Ok so I replaced U51 we have some progress! - Still remaining out are all the interior letters of the digit h,j,k,r,p,n of Display 2

    IMG_3584 (resized).JPG

    #11 4 years ago

    So if Im looking at this correctly it looks like they go to connector J3 to IJ22 pins: 10 (dot') -- 9 (r') -- 8(p') -- 7(n') -- 6(m') -- 5(k') -- 4(j') -- 3(h') Which all look like the are controlled by PIA U42.

    Going to test these pins at IJ22 and see what we get with all digit segments on.

    #12 4 years ago

    So here's a dumb question - does the bottom display even use the interior segments in the software or test mode - through all the menus and when I start a game I haven't seen where it uses any of those special characters.

    #13 4 years ago
    Quoted from fusion301:

    So here's a dumb question - does the bottom display even use the interior segments in the software or test mode - through all the menus and when I start a game I haven't seen where it uses any of those special characters.

    Nope, not used. Looks like you have fixed it!

    #14 4 years ago

    Great.. Big thanks to GRUMPY for taking the time to teach me how to use the logic probe and trouble shoot these displays. This was all a direct result of battery damage on the CPU so if you have display issues and battery damage, this could be your problem.

    The Jackpot display was just broken, I replaced it with another 7 digit display and everything is working.

    #15 4 years ago
    Quoted from fusion301:

    Ok so I replaced U51 we have some progress!

    Looks like its time for some pinball!!!
    Enjoy your hard work.

    3 weeks later
    #16 4 years ago

    GRUMPY i am posting a followup question here since it's related to fusion301 issue.

    My Police Force has now lost the d segment on the bottom display. I used a logic probe to verify pulsing at J-3 pin 5 so my problem is on the display board. I checked the output of pins 6 (d),4 (c),15 (b) and 2(a) on U11 and they are all pulsing so next up is U19 however it's -100vdc so logic probe isnt going to work here?

    Looks like the only things left are U19, R59 (which reads 8.34k ) and the actual display glass. There is no damage to the traces on the display board.

    I have seen the 'd' segment flicker on a couple times while testing but seemingly at random and not for long. I have had this game a couple years and this is the first I have seen this issue

    The bottom display is original. TNT replaced the upper display in 2000 based on the sticker

    #17 4 years ago
    Quoted from boscokid:

    so next up is U19 however it's -100vdc so logic probe isnt going to work here?

    You can check pin 2 of U-19 with your logic probe just to make sure it has pulses, if no pulses a bad trace or cold solder joint. If you have pulses there and your display is crisp and bright I would change U-19. You can also lock display on number 8 and use your DMM set on 200 volts DC and check pin 18 on display 1 then compare it to display 2. If they are the same then its a display problem, but remember there is a lot a fluctuations when checking voltage on displays because they are strobed on and off. Hope that helps.

    #18 4 years ago

    I get pulses at U19 pin 2. Display is crisp and bright.

    This may be a dumb question but how do I determine pin numbers on the glass? Didn't see any clues in the manual or on the board, is pin 18 just the 18th from the left? If that's the case it looks like I am getting 4.87v on both display 1 & 2

    display (resized).jpg

    #19 4 years ago

    Pin #1 is on the shooter lane side. I think you are on pin #72.

    #20 4 years ago

    The 18th pin from the right on the bottom display is -9.8v
    The 18th pin from the right on the top display is -64.4v

    So that confirms your theory that U19 needs to be replaced?

    #21 4 years ago
    Quoted from boscokid:

    So that confirms your theory that U19 needs to be replaced?

    Yes sir. U-19 is a pain to get at so take your time.

    1 week later
    #22 4 years ago

    Well I replaced U19 and 'd' segment still not lit on the bottom display.
    Went back and verified pulses at U19 pin 2
    Went back and checked voltages at pin 18 on upper and lower and got -5.4 on the lower and -65 on the upper
    I measured the resister on the bottom display R59 and get 8.43
    I measured the resister on the top display R42 ( i think) and get 8.10
    verified continuity between U19 pin 2 and bottom display pin 18 with a meter - they also visually look ok

    so now what? The U19 was date correct 9103 and manufactured in Philippines

    I swapped my Jokerz! display into Police Force and the bottom display worked fine so the problem is still on the display board

    when swapping the police force display to jokerz the bottom 'd' segment is still out

    #23 4 years ago

    Well I think that it's not your lucky day. Your display segment must be shorted out and pulling the signal down. Now your left with replacing the display. Is it worth your time and money? A new display is over 100.00 + shipping.

    #24 4 years ago

    Thanks for a the help. Doubt its worth seeking out a new display glass at that price, so I will look at my other options.

    #25 4 years ago

    Sometimes you can find a used one for less. You can wait until for it to get worse and then replace it with an LED version.

    8 months later
    #26 3 years ago

    I'm going to revive this thread with a similar issue I am having with my Whirlwind display. The top row lights the "d" segment inappropriately to result in some odd spelling. Some of the segments are either lightly lit (notice the "L" in ALTERED) or are lit and shouldn't be, or are missing altogether (check our the WHIRLWIND spelling and the segment missing at the bottom of the "I").

    In test mode, all of the segments work. I have reseated connectors and there was no change. Any help would be appreciated regarding where to look next.

    IMG_0212 (resized).JPG

    IMG_0213 (resized).JPG

    IMG_0214 (resized).JPG

    #27 3 years ago

    I'd start with a new ribbon cable. Or flip your current one end for end and see if the problem changes.

    #28 3 years ago
    Quoted from gutz:

    I'd start with a new ribbon cable. Or flip your current one end for end and see if the problem changes.

    Flipped the cable. Problem solved. Thanks for the tip!

    Hey there! Got a moment?

    Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside