Goblins Coin Up Problem - New New Evidence!

So tonight I was able to connect an alligator clip to the negative lead of the cap facing the card edge and touch the other end to the exposed pcb pad of pin 18 and nothing happened.

What does this mean?
Means your problem is on the pcb. although that was previously determined by the coining up by itself. Symptom changed from not coining up consistently to coining up by itself.

The problem is that you want the ready solution.I'm sure (and schematics speaks clear) the problem is in the custom resistor/capacitor array or the 74LS367 after this.But, you know, I'm saying this remotely so cooperation is needed from you too.Do you have a logic probe to check what I said?

Caius is giving you the next step.
 
The problem is that you want the ready solution.I'm sure (and schematics speaks clear) the problem is in the custom resistor/capacitor array or the 74LS367 after this.But, you know, I'm saying this remotely so cooperation is needed from you too.Do you have a logic probe to check what I said?

I don't own a logic probe to investigate further. And even if I bought one I'm unsure what to do to be honest. I may have to outsource this work.

I do appreciate all the helpful advice on this guys....truly I do. KLOVERS kick ass
 
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logic probes are simple. its just there name that makes them sound complicated. there are 3 connections on them one gets hooked to +5 one gets connected to gnd and the probe touches whatever you are testing. the probe indicates what the logic level is at the point you are testing. translation is it tels you if you have enough voltage at the point you are touching if it registers as a one or if the point has low enough voltage to be 0. other readings is pulsing which means a signal is occuring and you are seeing changes from 1 to 0 and back. if you get no light at all then your connection is floating and not connected to anything no ground connection or any incoming voltage open circuits
 
Hey! Got directed here from your email. Nice the thread gives a pretty accurate idea of what's going on.

Here's how this works. RC5 is a resistor capacitor network that holds the value of Coin 1 and Coin 2 high until it gets shorted by the coin switch. That is, it keeps the line at 5V, until the switch closes and it becomes 0V. If anything is wrong with RC5, the input line "floats." This means the cabinet wiring basically becomes an antenna and any stray noise can trigger a coin input. Alternatively, if RC5 is not working, it cannot coin up because it cannot toggle between 5V and 0V, because nothing is giving it 5V. RC5 is the most likely cause.

The "input chip" is 8A, the 74LS367. This chip interprets these 5V / 0V transistions and puts the information right on the data bus back to the processor. Since this is the main data bus, and you aren't having any problems booting, this is why we think there is not a problem on the data bus and it is possible you are having a problem with 8A.

It is unlikely, although possible that RA3 is bad, but I doubt it, even though I said it was likely in the email. I think it is unlikely because it sounds like your other inputs are working properly, and the thing boots.

A third option would be chip 73LS138 at 3A. This chip determines which input chip (4A, 5A, or 8A) gets read. If the enable line is not strong, you will have intermittent problems with both coins, and player 1 and 2 select buttons.

I am referencing this schematic, page 5
https://www.arcade-museum.com/manuals-videogames/G/Ghosts N Goblins Schematics.pdf

All that to say, replace one at a time:
RC5,
8A
3A

in that order and I would be shocked if that didn't resolve the issue.

-GB
 
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Hey! Got directed here from your email. Nice the thread gives a pretty accurate idea of what's going on.

Here's how this works. RC5 is a resistor capacitor network that holds the value of Coin 1 and Coin 2 high until it gets shorted by the coin switch. That is, it keeps the line at 5V, until the switch closes and it becomes 0V. If anything is wrong with RC5, the input line "floats." This means the cabinet wiring basically becomes an antenna and any stray noise can trigger a coin input. Alternatively, if RC5 is not working, it cannot coin up because it cannot toggle between 5V and 0V, because nothing is giving it 5V. RC5 is the most likely cause.

The "input chip" is 8A, the 74LS367. This chip interprets these 5V / 0V transistions and puts the information right on the data bus back to the processor. Since this is the main data bus, and you aren't having any problems booting, this is why we think there is not a problem on the data bus and it is possible you are having a problem with 8A.

It is unlikely, although possible that RA3 is bad, but I doubt it, even though I said it was likely in the email. I think it is unlikely because it sounds like your other inputs are working properly, and the thing boots.

A third option would be chip 73LS138 at 3A. This chip determines which input chip (4A, 5A, or 8A) gets read. If the enable line is not strong, you will have intermittent problems with both coins, and player 1 and 2 select buttons.

I am referencing this schematic, page 5
https://www.arcade-museum.com/manuals-videogames/G/Ghosts N Goblins Schematics.pdf

All that to say, replace one at a time:
RC5,
8A
3A

in that order and I would be shocked if that didn't resolve the issue.

-GB

Me too.

Most parts are cheep and easy to find.
 
Parts

Does anyone know a single source where I could buy the RC5, 74LS367 input chip and the 73LS138?

I'm in the mood to get this resolved and put her to bed.
 
The logic chips can easily be had from places like Farnell, Digikey and Mouser, resistor arrays are a little bit more difficult since they're made to order for a purpose, you'll need to figure out which resistors are in the array itself, preferably work out which one is faulty and replace it.

You can do this by measuring from the coin input pin on the edge connector to each pin on the resistor array to see if any are a vastly different resistance, and likewise the resistors to the ground pin on the edge connector
 
The logic chips can easily be had from places like Farnell, Digikey and Mouser, resistor arrays are a little bit more difficult since they're made to order for a purpose, you'll need to figure out which resistors are in the array itself, preferably work out which one is faulty and replace it.

You can do this by measuring from the coin input pin on the edge connector to each pin on the resistor array to see if any are a vastly different resistance, and likewise the resistors to the ground pin on the edge connector

So the RC5 is an array of resistors? And it's located on the board at position C5? Does it look like the pic I'm attaching below?
 

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No, that's a simple bunch of resistors (maybe put in series or parallel).A resistor array is something like this:

10855-01d.jpg


The peculiarity of the ones used on your board (like many others from differrent arcade manufacturers) is that they are are not standard arrays that you can find of the market (let's say a 10KOhm bussed or isolated) but they are custom and often they contain also filter capacitors.The ones on your board are located near the JAMMA adge :

1059454809.jpg


I have reproduced many of these arrays and they are essentially the same.First of all they act as pull-up so, usually, the first pin is tied to VCC.Then each input from JAMMA connector is tied to a pin of the array (which usually is connected to a 1Kohm resistor) then the adiacent pin acts as output and usually it's connected to a 220 Ohm resistor.Now I don't have any Capcom board to experiment with but it should be pretty simple to reproduce this array with simple axial resistors.
 
Thanks caius for the explanation.

So if I can't find the custom RC5 resistor array on the market, what is the best way for me to get a new one installed on my board?

Also, I can't seemed to source the 73LS138.
 
Thanks caius for the explanation.

So if I can't find the custom RC5 resistor array on the market, what is the best way for me to get a new one installed on my board?


You have two options : take a spare from another Capcom board (this array is used on may of them) or analyze and reproduce it with axial resistors.By the way, could you report the exact part name maked on it?

Also, I can't seemed to source the 73LS138.

That's impossible, this TTL is widely used.Do a better search and it will pop up.
 
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Guess I will keep my eyes open for a GNG PCB or another Capcom PCB going up for sale.

Is this the exact 74LS367 chip I need? I've seen a few different designs.....
 

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74LS138.
The 74LS367 you posted is fine.As for custom resistor array, look at your board and report here the marking, I want to check what other boards carry it
 
74LS138.
The 74LS367 you posted is fine.As for custom resistor array, look at your board and report here the marking, I want to check what other boards carry it

My GNG machine is on location at a bar. But next time I go in there I will snap pics of the custom resistor array area by the edge connector and post them here.

Thanks for clearing up the other part # for me. Gonna order those soon.
 
Hey! Got directed here from your email. Nice the thread gives a pretty accurate idea of what's going on.

Here's how this works. RC5 is a resistor capacitor network that holds the value of Coin 1 and Coin 2 high until it gets shorted by the coin switch. That is, it keeps the line at 5V, until the switch closes and it becomes 0V. If anything is wrong with RC5, the input line "floats." This means the cabinet wiring basically becomes an antenna and any stray noise can trigger a coin input. Alternatively, if RC5 is not working, it cannot coin up because it cannot toggle between 5V and 0V, because nothing is giving it 5V. RC5 is the most likely cause.

The "input chip" is 8A, the 74LS367. This chip interprets these 5V / 0V transistions and puts the information right on the data bus back to the processor. Since this is the main data bus, and you aren't having any problems booting, this is why we think there is not a problem on the data bus and it is possible you are having a problem with 8A.

It is unlikely, although possible that RA3 is bad, but I doubt it, even though I said it was likely in the email. I think it is unlikely because it sounds like your other inputs are working properly, and the thing boots.

A third option would be chip 73LS138 at 3A. This chip determines which input chip (4A, 5A, or 8A) gets read. If the enable line is not strong, you will have intermittent problems with both coins, and player 1 and 2 select buttons.

I am referencing this schematic, page 5
https://www.arcade-museum.com/manuals-videogames/G/Ghosts N Goblins Schematics.pdf

All that to say, replace one at a time:
RC5,
8A
3A

in that order and I would be shocked if that didn't resolve the issue.

-GB


I've replaced the resistor pack at RC5 and the chips at 8A and 3A. The old chips at 8A and 3A tested fine btw. Put repaired boards back in AND the game is still not coining up properly. Ugh.

Anything else I can do folks?

Should I replace RA3?

Was the tech at Funspot correct when he said it is probably the "interface chip" - whatever that is.

Are Goblins inside the cab playing with the IC's?
 
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