(Topic ID: 88787)

Gottlieb system 1 display issue - small transformer (B-17921)


By pinhead_jack

4 years ago



Topic Stats

  • 25 posts
  • 12 Pinsiders participating
  • Latest reply 4 years ago by nasco62
  • Topic is favorited by 2 Pinsiders

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#1 4 years ago

Hello All,

I have a Cleopatra SS that I am working on and I am running into a display problem which seems to be power related.

Following the steps on the pinrepair site (http://www.pinrepair.com/sys1/index.htm) I have checked the power levels on the power supply board and discovered that my 60 and 42 volt connections are low. The 60 is reading at 43.8 and the 42 is reading at 25. The top power connector, to the CPU (5 and 12), is good and reading right where they need to be. The issue is limited to the 60 and 42 volts on the side connection.

I tested the power cable (A2J1 I believe) that feeds the power supply board and the problem exists at that point, which takes the power supply board itself out of the equation as the source of the problem. I don’t think there is anything else between the small transformer and the power supply board that can cause a problem.

If that is true then it means that my small transformer (B-17921) is no good. I have looked for a replacement and I cannot find one available anywhere. Does anyone know if a system 80 transformer will work in a system 1? I saw a small transformer from a Counterforce machine (#B19548) for sale but I don’t know if it will work as a replacement for the small transformer that originally came with Cleopatra (B-17921) as I cannot find a schematic for Counterforce to see how the power pins out.

Is there another suitable replacement transformer that I can put in its place to try and correct the power issue?

Thanks!

#2 4 years ago
Quoted from pinhead_jack:

Following the steps on the pinrepair site (http://www.pinrepair.com/sys1/index.htm) I have checked the power levels on the power supply board and discovered that my 60 and 42 volt connections are low. The 60 is reading at 43.8 and the 42 is reading at 25. The top power connector, to the CPU (5 and 12), is good and reading right where they need to be. The issue is limited to the 60 and 42 volts on the side connection.

Where are you connecting your ground lead when taking these readings? On the top connector (+5v, 12v), you can use the cabinet ground. On the side connector, you need to use the ground on that connector to get the correct reading. Also, on the bottom connector, it's all A/C, so you never want to use the cabinet ground there.

#3 4 years ago

You could remove the Voltage in connector from the power supply and read the voltage at the transformer. If the 62V tap is not close then yeah transformer problem.

1 month later
#4 4 years ago

Would running a third transformer inside the cabinet be an issue? I bought the owner’s manual for counterforce to find the correct 60v windings and I was thinking I could install it into the cabinet and hook up the 60v only and see if it corrected my display problem. But will a third transformer installed be a problem?

All of this is based on the Counterforce transformer being good of course.

#5 4 years ago

Forget a Counterforce "few" minutes... )

and read carefully...

Quoted from CNKay:

You could remove the Voltage in connector from the power supply and read the voltage at the transformer. If the 62V tap is not close then yeah transformer problem.

(it's a "story" about Cleopatra's transformer ! )

Greetings from Croatia

#6 4 years ago
Quoted from cro_pinman:

Forget a Counterforce "few" minutes... )
and read carefully...

(it's a "story" about Cleopatra's transformer ! )
Greetings from Croatia

went over my head

#7 4 years ago
Quoted from maddog14:

went over my head

haha - I am in the same boat. I reread it three times thinking I was missing something but I am just missing the point cro_pinman is getting at.

I checked the power at points coming off the power board (per the video on pinrepair) and once I saw it was low I verified the voltage coming into the board on the cable that feeds it. the cable feeding the power board is the same as what is coming off (42 for 60v, 26 for 42v). So this is why I am looking to replace the transformer.

I understand measuring voltage directly off the transformer for everything but the 69v rail. For everything else it is using the common ground on the transformer + 1 winding of the given voltage. But the 69v line uses two windings across the back of the transformer, how do you measure that?

#8 4 years ago

did you measure the ac voltage for the 60 VDC disconnected from the power supply?
tthe PS could be loading down the ac input. Need to take the load off to see what input AC voltage is.

since the 60 and 42 volts are low from the transformer, did you check the transformer's input voltage.
Is it 120 VAC. Are the correct taps being used on the transformer?

#9 4 years ago
Quoted from pinhead_jack:

I understand measuring voltage directly off the transformer for everything but the 69v rail. For everything else it is using the common ground on the transformer + 1 winding of the given voltage. But the 69v line uses two windings across the back of the transformer, how do you measure that?

The transformer voltages are all ac and do are not measured to common ground. just measure voltage on both ends of the windings.

#10 4 years ago

remove power supply AC input connector , what is the AC voltage on pins 6 and 7 of the female connector? (should be the last 2 pins on the right). the manual says it should be 69 AC volts.

#11 4 years ago
Quoted from pinballdaveh:

remove power supply AC input connector , what is the AC voltage on pins 6 and 7 of the female connector? (should be the last 2 pins on the right). the manual says it should be 69 AC volts.

It is reading 43.8 volts.

#12 4 years ago
Quoted from pinhead_jack:

It is reading 43.8 volts.

This is with the A2J1 connector to the power supply disconnected, correct?

With A2J1 disconnected from the power supply measure the following:
A2J1-1 to A2J1-2 for ~ 11.5 VAC
A2J1-4 to A2J1-5 for ~ 14 VAC

I'm sure they are OK as you state your +5VDC and -12VDC are OK.
so if your 11.5VAC and 14 VAC are OK, then maybe your transformer,
at least for the 69VAC output is defective.

Have you done continuity yet. Just to make double sure.
Power off. remove 1/4 amp fuse. from the fuse holder side that does not connect to the transformer, measure continuity from that point to A2J1-6.
From the transformer tap 8 to A2J1-7.

Alternately if you could find a small transformer that outputted between 65 and 70 VAC, you could hack that in just to supply the needed AC voltage.
I'll look around at some of the surplus places and see what I can find. Current output is pretty low as well.

#13 4 years ago

Might be easier finding two 35 VAC outs and putting the outputs in series or three 24 VAC transformers outputs put in series.

Here's 24 VAC out at 2 amp, plenty of juice, for $9, three for $27 plus shipping.
http://www.mpja.com/24V-2A-Center-Tapped-12-0-12-Transformer/productinfo/7844%20TR/#

Looking around you could probably find something cheaper.
Ham swap meets (don't know how many are still out there ) is a good place to find transformers and electronic parts.
Checking the big catalogue guys, Mouser, Newark, Allied, DigiKey, Jameco, you may find something suitable.

#14 4 years ago

what is the AC voltage coming out of the line filter? it can be measured at the convience outlet. what transformer primary voltage taps are being used? 115v on both?

#15 4 years ago

The P/N "B-19325" is equivalent, but it's just as hard to find as the B-17921. BTW, there is one of those available on Ebay now, but they want $150 for it

#17 4 years ago

what if i had one .. but it was in australia? do you want it bad enough to pay postage from here?

#18 4 years ago

pinhead, how are you making out on this?

#19 4 years ago

Sorry for the delay in getting back to the project and back to all of you on my progress. I greatly appreciate all the help you have offered up! After the feedback here I re-measured all the touch points on the power supply board (using the guide on pinrepair) and confirmed my original findings which showed me that the 60v and 42v lines were low.

I proceeded to add in the other small transformer (B-19548) and connect the 69v lines only. Now when I measured on the power board I am now getting the right voltages all the way across (+5, -12, 60, 42). YEAH!

But when I turned on the power I realized that I am getting a solenoid locking on (the ball eject to the shooting lane). I have not hooked up the MPU or driver board to the power source yet at this point so this solenoid is either being fed from the general illumination (which I didn't think any solenoid is), the solenoid has gone bad, or I am missing something?? Once I realized it was locked on I shut the game off immediately before it burned up. It was on for a minute while I checked voltages on the power supply.

Again, at this point I have the right voltages, I have not connected anything to the power supply board, and I have a solenoid locking on when I turn the machine on. Is the assumption that the solenoid has gone bad? Any other thoughts?

Thank you for all the help!

#20 4 years ago

Sounds like you've got a short. Check the area near your solenoid tabs for anything touching. If nothing, check wiring leading up to the coil.

#21 4 years ago

I figured I should also clarify: I don't have schematics for this game, nor did I mention that it could be a diode issue. Without mpu and driver board hooked up, though, no controlled solenoids should be moving.

#22 4 years ago

Update: It looks like I measured wrong yesterday on the voltage. This morning I pulled the 25v solenoid fuse and turned the game on (with the two out plugs from the power supply board unhooked, and when I measured across the top connector I saw that the 5v is fine but there was no -12v activity.

I have a different power supply board I am going to test with but where does the -12 come from? Any thoughts on what I should look at? Could this be the solenoid issue?

I feel like I am getting very close...

#23 4 years ago

ug, I am at a loss at this point, I think I have just reached a knowledge limit. I am not sure what to look to troubleshoot my two issues, which could be related for all I know.

Issue 1: My out hole solenoid locks on when I turn on the game. I have physically unconnected everything from the power supply and it still locks on. Could it be the solenoid or diode on the solenoid? Could this be the result of a bad rectifier or transformer? I am not sure where to look.

Issue 2: I am not getting any reading on the -12 volt line on the power supply. I pulled the 25v solenoid fuse out of the bottom panel so I didn't burn out the solenoid in issue 1 above and plugged in the input line to the power supply. When I tested the top connecter I saw that my two 5v lines were fine but I could not get a reading on the -12v line.

I went from thinking I am close to feeling like I am getting further into the abyss on this one. I appreciate any suggestions you may have.

#24 4 years ago

With a bad diode it could cause all kinds of nasty problems, but I don't think this is one.

Your solenoid locking on is probably a short to ground somewhere. Look for stuff that's touching first, then carefully inspect the wiring. A schematic will help you tremendously. Look for what is connected and what connector off the power supply (eventually) feeds to the coil.

Your missing - voltage, I'd have to look at a schematic to see how that's created, but might be a bad filter capacitor or rectifier... Just thoughts. Sorry I can't say for certain.

3 months later
#25 4 years ago
Quoted from pinhead_jack:

ug, I am at a loss at this point, I think I have just reached a knowledge limit. I am not sure what to look to troubleshoot my two issues, which could be related for all I know.
Issue 1: My out hole solenoid locks on when I turn on the game. I have physically unconnected everything from the power supply and it still locks on. Could it be the solenoid or diode on the solenoid? Could this be the result of a bad rectifier or transformer? I am not sure where to look.
Issue 2: I am not getting any reading on the -12 volt line on the power supply. I pulled the 25v solenoid fuse out of the bottom panel so I didn't burn out the solenoid in issue 1 above and plugged in the input line to the power supply. When I tested the top connecter I saw that my two 5v lines were fine but I could not get a reading on the -12v line.
I went from thinking I am close to feeling like I am getting further into the abyss on this one. I appreciate any suggestions you may have.

Where did you get to with this am having similar issues with my Charlies Angels

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