mother of God.. Monaco GP.. please help me.

[vintagegamer]

I am at my wits end with this game.  I have been working on it for 3 mos, everything works but COINING UP.  I was told to replace 2 IC's on one of the PCBs and I did, and after that it did start a few games sporadically, but now I'm right back where I was.

This game is so godddammmmmmmmmm frustrating.  I think I'd be happier if it wasn't working at all, rather than have everything work but the GAME START!

Help me please!  I've been ping ponging around between 4 sites for help!  Please make it stop!!

[vintagegamer]

Forgot to mention specifically what I have done:

1. checked in between the front and rear sections for pinched or broken wires
2. replaced the chips on PCB 96577 at locations IC32 and IC37
3. checked that the coin switch is a good working one
4. checked for voltages at the coin switch and they are all in check

I've done about a bajillion other things troubleshooting it also, but can't remember them all at the moment.  I'm sure I will if you ask me though!

Below is a pic of basically what the unit looks like (mine is missing the smoked plexi on the back)

[vintagegamer]

Well uh, wow.

[jennifer]

           Recheching for a broken wire [especially around the coin door hinge] would be my thought, looking carfully for a "almost" break,
Did the game ever work, or did you get it this way?

[lilshawn]

everything works but COINING UP

can you jump it at the jamma connector and get it to register a coin?

[vintagegamer]

           Recheching for a broken wire [especially around the coin door hinge] would be my thought, looking carfully for a "almost" break,
Did the game ever work, or did you get it this way?

It came to me this way.

[vintagegamer]

everything works but COINING UP

can you jump it at the jamma connector and get it to register a coin?

Sadly this is pre-jamma so no jamma connector.

[Nephasth]

Sadly this is pre-jamma so no jamma connector.

Well, judging by the manual, looks like you could jump pins 3 and 5 on the 12 pin IC board connector (natural color, not brown. According to the manual). That would simulate a coin up while eliminating any problems that might exist in the wiring.

Also, there is a troubleshooting tree for this. It is as follows: Game does not coin up --> Check coin switch. If bad, change coin switch. If good, check wiring harness. If bad, repair harness. If good, check for 5v on both terminals of coin counter. If bad, repair PC Board 96578-P. If good, change meter.

Hope this helps.

[vintagegamer]

Sadly this is pre-jamma so no jamma connector.

Well, judging by the manual, looks like you could jump pins 3 and 5 on the 12 pin IC board connector (natural color, not brown. According to the manual). That would simulate a coin up while eliminating any problems that might exist in the wiring.

Also, there is a troubleshooting tree for this. It is as follows: Game does not coin up --> Check coin switch. If bad, change coin switch. If good, check wiring harness. If bad, repair harness. If good, check for 5v on both terminals of coin counter. If bad, repair PC Board 96578-P. If good, change meter.

Hope this helps.

Thanks for the help- where did you find the troubleshooting tree at?  I did not see that in the manual?  I'll have to try jumping the 3 and 5 pins that you reference.  I know exactly where that is. 

[vintagegamer]

Sadly this is pre-jamma so no jamma connector.

Well, judging by the manual, looks like you could jump pins 3 and 5 on the 12 pin IC board connector (natural color, not brown. According to the manual). That would simulate a coin up while eliminating any problems that might exist in the wiring.

Also, there is a troubleshooting tree for this. It is as follows: Game does not coin up --> Check coin switch. If bad, change coin switch. If good, check wiring harness. If bad, repair harness. If good, check for 5v on both terminals of coin counter. If bad, repair PC Board 96578-P. If good, change meter.

Hope this helps.

I also forgot to mention that I swapped out the IC at location 18 on 96578-P as it relates to the coin up-game, but it made no difference.

[vintagegamer]

Sadly this is pre-jamma so no jamma connector.

Well, judging by the manual, looks like you could jump pins 3 and 5 on the 12 pin IC board connector (natural color, not brown. According to the manual). That would simulate a coin up while eliminating any problems that might exist in the wiring.

Also, there is a troubleshooting tree for this. It is as follows: Game does not coin up --> Check coin switch. If bad, change coin switch. If good, check wiring harness. If bad, repair harness. If good, check for 5v on both terminals of coin counter. If bad, repair PC Board 96578-P. If good, change meter.

Hope this helps.

Just found the tree you were referencing.

[Nephasth]

Without having your machine in front of me, but with the information you've given, I'm leaning towards a bad coin counter. I'd check for the 5v at the counter's terminals real quick.

[vintagegamer]

Without having your machine in front of me, but with the information you've given, I'm leaning towards a bad coin counter. I'd check for the 5v at the counter's terminals real quick.

not to doubt your expertise in any way, but if the coin meter is registering a credit, what leads you to believe that is the culprit? maybe just bc the 'out' on the meter is failing? i've never had a bad meter before so with the probs i'm having i'll believe anything!

[Nephasth]

not to doubt your expertise in any way, but if the coin meter is registering a credit, what leads you to believe that is the culprit? maybe just bc the 'out' on the meter is failing? i've never had a bad meter before so with the probs i'm having i'll believe anything!

I am by no means an expert. I have been, however, a mechanic for numerous years and have done a ton of electrical and electronic troubleshooting. My experience has taught me that manufacturer's troubleshooting steps will lead you to the proper repair 99% of the time. You didn't state before that the meter was counting coins. The same steps are for not coining up as well as the meter not counting, which tells me that one problem could cause two different issues. With the machine powered up, you should have 5v at BOTH of the meter's terminals. The steps say if you do have 5v at both terminals, replace the meter. If you don't have the 5v on both terminals, there is something wrong with PC Board 96578-P. Your voltage at the meter may be below the specified 5v, but high enough to roll your meter over. The IC you changed may not have been the problem, there may be a different problem with the board. Maybe a bad solder joint? Have you checked the voltage at the meter terminals?

[BobA]

If the meter is counting then the first stage of the coin input is working.   The coin meter is pulled to ground when a coin is sensed.  There are a bunch of other inputs that look like they can coin up a game without hitting the counter.  Have you tired the credit switch or the test switch which feed into the same gate and what were the results?  Not sure of your IC reference numbers since I only glanced at the coin circuit and the gate in question looks like a 7411 marked 125 on the circuit diagram.

[vintagegamer]

not to doubt your expertise in any way, but if the coin meter is registering a credit, what leads you to believe that is the culprit? maybe just bc the 'out' on the meter is failing? i've never had a bad meter before so with the probs i'm having i'll believe anything!

I am by no means an expert. I have been, however, a mechanic for numerous years and have done a ton of electrical and electronic troubleshooting. My experience has taught me that manufacturer's troubleshooting steps will lead you to the proper repair 99% of the time. You didn't state before that the meter was counting coins. The same steps are for not coining up as well as the meter not counting, which tells me that one problem could cause two different issues. With the machine powered up, you should have 5v at BOTH of the meter's terminals. The steps say if you do have 5v at both terminals, replace the meter. If you don't have the 5v on both terminals, there is something wrong with PC Board 96578-P. Your voltage at the meter may be below the specified 5v, but high enough to roll your meter over. The IC you changed may not have been the problem, there may be a different problem with the board. Maybe a bad solder joint? Have you checked the voltage at the meter terminals?

Greatly appreciated N- I have not yet gotten to meter the voltage at the coin counter-meter, but will do that this week and advise.  Thank you for the help!

[vintagegamer]

Have you tired the credit switch or the test switch which feed into the same gate and what were the results?  Not sure of your IC reference numbers since I only glanced at the coin circuit and the gate in question looks like a 7411 marked 125 on the circuit diagram.

Can you point out for me where you're seeing the 7411 at 125 (ie which page of manual or which board)?  I have not located that one yet.  

The credit-test switch works 'sometimes', with about the same frequency as the coin switch.  Also, there are 2 service-credit switches, one by the console where you sit, and one in the back of the game by the PCBs.  The one that's in the back is not getting any power at all for some reason.  The one in the console is getting power.

UPDATE: I see the 7411 chip now.  I'll see if I can get a new one and swap it out.

[jennifer]

       You should check it out first, input output, maybe spray it with freeze, could be a thermal problem.

[Nephasth]

       You should check it out first, input output, maybe spray it with freeze, could be a thermal problem.

Agreed. No sense in changing out good parts.

[vintagegamer]

       You should check it out first, input output, maybe spray it with freeze, could be a thermal problem.

You guys are in a much higher bracket than me.  I don't even own freeze spray!  Up until this year, if it wasn't a socketed chip, I didn't know what to do with it. 

[jennifer]

          Do you have a multimeter?

[vintagegamer]

          Do you have a multimeter?

Yep that I do have and do know how to use it as well.   

[BobA]

Do you have a logic probe?  That could speed up your troubleshooting of digital logic circuits quite significantly.

[vintagegamer]

Do you have a logic probe?  That could speed up your troubleshooting of digital logic circuits quite significantly.

Unfortunately that is something I do not have.

[Nephasth]

Did you ever figure this one out?