Mystic
Bally, 1980#Mystic Bally ss. The ones digit went out on all displays this afternoon. I had been replacing the lamp socket in a pop bumper. Also, I messed around with the game settings some, on the Alltek board.
Could use some guidance.
Also, the sound is cutting out, as the machine counts down the bonuses. A week or so ago, the sound went real weird, like the pitch was greatly increased. That only lasted for a few games.
Quoted from undrdog:The ones digit went out on all displays this afternoon.
See here from earlier today:
https://pinside.com/pinball/forum/topic/bally-ek-connector-issue
Quoted from undrdog:Is there a trick to it? Do I need to bare the wire or get a special tool?
You don't need to bare the wire. Provided you didn't insert the wire with something too thick that may have spread the terminal in the connector (so it doesn't pierce the wire insulation), it should be ok but you better check continuity:
Grab your multimeter. Set it to low ohms range. Put one meter lead on the left side of resistor R1 shown in your picture above that's next to J1 pin 1. Insert the other meter lead in pin 4 at the displays connector. Do you get zero ohms reading (i.e. not open circuit).
For your sanity do the same with the 10's digit signal so you see how the meter should respond which is the right side of resistor R2 on the MPU board and pin 5 at the displays connectors.
It does go all the way through, but it’s hard to see in the picture because the end is bare wire. I should have trimmed it off.
I’ll play with the multimeter and report back.
Quench Well, this is weird.
If I am doing it correctly... and if you meant to say that the 10s digit is on the left side of resistor R2 facing the circuit board as it is attached to the machine, I get .7 at the 5th pin on the display unit. The meter doesn't budge from 1 (seems to be the default) on the left side of the R1 resistor and pin 4 at the display.
This is on the 200 setting of the multimeter, but changing that setting doesn't get me anything different on the left side of the R1 and pin 4 on the display unit. Or the right side of R1.
If, on the other hand you really meant the left side of resister R2, then all I get is the default 1 touching that to pin 5. Or pin 4 .
Just as a test, I touched the two leads to some braided ground wire, about an inch apart, and got a different reading than the default 1.
Turning the multimeter to the diode setting, I get 1205 probing both sides of R1 and 1200 for both sides of R2. In case that helps any.
Quoted from undrdog:If I am doing it correctly... and if you meant to say that the 10s digit is on the left side of resistor R2 facing the circuit board as it is attached to the machine, I get .7 at the 5th pin on the display unit.
On the 200 ohm resistance range (this is the correct setting to test continuity), your meter is telling you that on the 10's digit enable signal, there's 0.7 ohms resistance which is good continuity from the MPU board to the displays.
Touch both your meter leads together in resistance mode, the reading you get is a closed (short) circuit. That reading or very close to is what you're looking for when testing continuity.
Quoted from undrdog:The meter doesn't budge from 1 (seems to be the default) on the left side of the R1 resistor and pin 4 at the display.
If the meter isn't budging from "1", that tells you there's an open circuit on that black wire between the left leg of R1 and the displays at pin 4. You need to find out where the break in connection is.
Where you've reinserted the black wire into the J1 pin 1 terminal, put your meter lead in the cut end of the black pin 1 wire where you should see the internal copper core of the wire. Put the other meter lead on the left leg of R1. If the meter still doesn't budge and assuming you've made contact with the black wire core, then the re-insertion of the wire into the connector hasn't made contact with the terminal in the connector.
If you do measure around 0.7 ohms, then you need to follow that black wire downstream to the displays to find where it's lost connectivity.
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Kittery, ME