(Topic ID: 290858)

Bally Night Rider SS - 10s digit display issue, help requested

By Bchop7

8 months ago


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  • 22 posts
  • 7 Pinsiders participating
  • Latest reply 7 months ago by Bchop7
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#1 8 months ago

I have a Bally Night Rider SS game that I have replaced all 5 of the displays with new low voltage LED displays built by Pinscore. Each display plugged in by itself works fine in every one of the 5 display slots (so they all work individually). And two displays plugged in at the same time in any position also seem to work fine. But once I add a 3rd display then ONLY the 10’s digit gets dimmer in that 3rd display. As I add the 4th and 5th display then 2 thru 5 (in wiring order) all get successively dimmer but only in the 10’s digit place. All other digits in all displays are fine. The game also has modern Alltek MPU and Solenoid Driver boards.
I have talked to Pinscore about this but they don’t have an answer. I sent a note to Alltek to see if maybe the MPU board might have the ability to cause this due to some type of control or timing issue but they said it wasn’t possible. So, I’m looking for some advice.

Pincore displays (resized).jpg
#2 8 months ago

What is your 5v rail reading with all displays running?

#3 8 months ago

probably a wire on 1 of the display connector since it works in player 1 . make sure power is off and check for loose wire

#4 8 months ago

Agree with Steamfitter. Everything else is good I think a loose 10s digit enable wire. On the older games before IDC connectors the wires are double crimped and daisy chained to the next display. Since the 1st player works start there at pin 5 and see if the wire crimped is loose.

#5 8 months ago

They're right. Disregard what I said. I was thinking you were losing the digit after adding more displays...what I was thinking didn't really make sense.

You should be able to turn the game off, and check continuity from pin 5, display 1, to pin 5 display 2. If you cant find the disconnect, you can always run a jumper between those and see if that clears the problem.

#6 8 months ago

Guys, thanks for the responses. I checked the 5V input to each of the 5 connected displays and the voltage is the same (not loaded down later in the series), I also jumpered the 5V from display 1 (which is fine) to display 5 with no effect. Not surprisingly as all the digits but the 10s digit are fine. I also tried to jumper the enable signal (J1 pin5) for the 10s digit from display 1 to display 5 with no effect. Note that if I only plug in the 5th display by itself (last in the series), the display works fine so that tells me it's not a poor connection as a result of the series wiring, I guess. And again, it's just the 10s digit. I have also wiggled all the wiring on all connectors to see if there was something loose, with no effect. Note when any two displays are connected in any two slots, they work, its just when more than two are connected, the 3rd one in line starts to dim, and when adding more displays the last ones in line get significantly more dim. Below are there results from a series of tests. Recall all the displays work individually. I am communicating with a guy at PINSCORE (display manufacturer) but he doesn't have an answer either.

Screen Shot 2021-03-21 at 7.53.30 PM (resized).pngScreen Shot 2021-03-21 at 7.54.19 PM (resized).png
#7 8 months ago

So if jumping 10 digit enable from display 1 to another display with weak '10' had no effect... maybe that 10 enable has a weak connection before it even gets to the displays? But if that was it, why is display 1 always good even if you have them all plugged in? Unless it's combo of weak connection before it gets to the displays + another weak connection(s) at the connectors. Oh well I tried. Maybe try jumping 10 enable to display with weak digit, from wherever 10 enable line actually originates at the board.

Funny how when there's a weak digit anywhere, the first display is always okay whether it's 1, 2 or 3.

#8 8 months ago

before you changed to the current displays, what did you have?

#9 8 months ago

Rikoshay Well, I had those old HV gas displays. Display 4 had half burned out ones 1's and 10s digits, and display 5 had a burned out 10s digit but the other displays were fine. Maybe coincidence on the 10s digit but I didn't have them getting dimmer. Since the new displays run on 5V it seems like they must be loading it down somehow, but I can't find a measurement that show's it.

#10 8 months ago

Add some dummy load to the 5v and see if gets worse? Try jumping 5v directly from the ps board to one of the dim displays and see if improves? But if was the 5v, why would it only affect that one digit...

#11 8 months ago

Since I did have two working HV gas displays, (thanks Rikoshay for the reminder), I added them into the mix with the LED displays. The two HV displays worked in every display slot and with every combination with adding 1, 2, or 3 of the LED displays. That tells me that the logic to the display boards (enable, blanking, etc) is not the problem. As for the LED displays, the results were similar to before. Any time there are more than 2 displays connected (ie, one LED and 2 HV, or 2 LED and 1 HV, etc), the LED display has a very dim 10s digit (HV displays work fine). And just one LED and one HV display connected are fine. So, again it appears something is getting loaded down on the LED board, but the voltage at the LED board input is right on 5V. Not sure what to do next.

#12 8 months ago

i feel for ya, this isn't of any help, but did have a similarish (that's a word) problem where when HV displays were in, the pin was perfect, but upon adding LED displays the mpu went into reboot.

checked the 5V which was at 5.08V.

at 2-3 LED displays installed they were perfect, add one more and reboot happened.

kept the HV displays in.

different brand manufacturer.

1 week later
#13 7 months ago

Try switching PIAs 1 and 2 (U10 and U11) on the MPU and retest with at least 3 LED displays.

#14 7 months ago
Quoted from KenH:

Try switching PIAs 1 and 2 (U10 and U11) on the MPU and retest with at least 3 LED displays.

He's got an Altek mpu, don't think that would apply, the chipset is totally different.

#15 7 months ago

The Alltek has two 6821 PIAs (just like the Bally board), but at U2 and U6. You can try swapping them.

#16 7 months ago

So do these aftermarket LED displays typically draw a whole bunch more 5v than an HV display does? Or just a little, or about the same?

#17 7 months ago
Quoted from frenchmarky:

So do these aftermarket LED displays typically draw a whole bunch more 5v than an HV display does? Or just a little, or about the same?

That's the thing about these LED displays. With all 5, they draw about 1 more amp than the plasmas. The existing LM323 5v regulator is spec'd at 3A max, and already providing about 2A to the game with plasma displays, so is pushed to its max of 3A with LEDs installed. If you're replacing the entire set, I always thought LEDs should have their own, dedicated 5v PS.

So your options are:

1. Leave as is (which may work, or may be problematic, stressing your regulator)

2. Replace the LM323 with a higher current device (impossible to find, but you may be able to use one of these https://www.ezsbc.com/product-category/voltage-regulators-2/)

3. Bypass the game 5v PS and add your own (an old PC PS would have more than enough capacity)

4. Put the displays on their own 5v 2A (minimum) PS

#18 7 months ago

While Pinside was down, the O.P posted his problem on other forums and a test determined the issue is with the 10's digit drive signal from the MPU board - he was asked to swap the PIAs but is yet to respond:

https://www.aussiearcade.com/forum/pinball/pinball-technical-and-repair-questions/2201757-bally-night-rider-ss-10s-digit-display-issue-need-help?p=2201933#post2201933

This is also likely a combinational issue with the Pinscore displays potentially putting more load on the digit drive signals.

Since only the 10's digit gets dimmer as more displays are added it says this isn't a 5V supply problem, otherwise all digits would get dimmer or worse the game continually crashing.

#19 7 months ago

I was kinda betting it was still a 10 digit drive board/connection problem + now seeing that these displays apparently can suck up a lot more 5v maybe it is only showing up because of the latter. And one would think a display with 40-year-newer devices would go easier on those drive signals, not harder (?)

But there are LED displays that say "Very low current usage, no worries for your 5v power regulator." So I'm only bettin' a nickel.

#20 7 months ago
Quoted from frenchmarky:

And one would think a display with 40-year-newer devices would go easier on those drive signals, not harder (?)

Schematics or pictures of the Pinscore circuit board would help
Their web site is just coming up empty.

Quoted from frenchmarky:

But there are LED displays that say "Very low current usage, no worries for your 5v power regulator." So I'm only bettin' a nickel.

A cached version of Pinscores web site states their displays are using efficient LED blocks that only consume 10mA per segment.

https://webcache.googleusercontent.com/search?q=cache:8kKm3Nf91_IJ:https://www.pinscore.com/technology/9/41-why-pinscore-leds-are-more-efficient

By my calculation displaying an '8' in every digit of each display will draw roughly 0.4 - 0.5 Amps. (7 segments in a digit * 10mA * 5 displays + some overhead). Only one digit at each display is active at any time - they're just refreshed fast enough in sequence that our eyes perceive them as static.

#21 7 months ago
Quoted from Quench:

By my calculation displaying...

Yeah, I see what you mean. If they only use about .5 amps for all five, that's not bad at all.

I multiplied the 6 digits in, and got over 2 amps, but that would not account for the multiplexing.

1 week later
#22 7 months ago

I got the problem fixed. Thank you for all the responses. “Quench” suggested I switch the MPU J1 pins between the 10s and 1000s enable signal and the problem moved to the 1000s digit! Meaning it had to be the MPU. I sent the MPU back to Allteksystems and evidently one MPU enable line output resistor (on the 10s digit) was burned out. I guess this was caused by one of the displays at some point. Don’t know if it was the original gas displays or what. Curious that it caused the resistor to reduce its value (from 1.2k ohms to 1.07k ohms) as opposed to becoming open, which you would expect. In any case, the new MPU board fixed the problem and all LED Pinscore displays work perfectly. Thanks all !!!!

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