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Addams Family Ground Fault

Andrew Prothero

Registered
Joined
May 7, 2017
Messages
28
Location
Bristol
Hi Guys,

So need your expert help again. On the weekend the Addams Family was getting a bit of use and stopped working. It has an error message saying...

Gnd. Fault Row 1, Stuck Closed

I’ve had a good scan for any loose wires under the playfield.

Not sure where to start.

I can’t get any of the menu controls to work it just states the error message.

Any help much appreciated.

Cheers

Andy
 
Taken from another thread ...........http://www.pinballinfo.com/community/threads/taf-fault-finding-guide.690/




Error Message: GND. Short Row 1 is Stuck Closed




Symptom: When you power up the machine we get this error message, "GND. Short Row 1 is stuck closed".

Chances are pretty good that if you can not cycle through any of the other test switches on the buttons inside the coin door that you have a blown driver on the WPC board. I would suspect U20 to be bad. This driver is a ULN2803. It is located on the WPC Power Driver Board. To replace, remove the driver board from the back box. Label all of the Molex connectors with a Sharpie pen first - this makes it easy to put everything back together. Then, locate the driver on the board (it will be labeled U20). Desolder it and put a new one in place. You may wish to install an 18 pin socket first. Put the board back in the back box.
 
Thanks for the reply, that’s probably past my skill level, I have located the ULN2803 , would it show any signs of being blown as it looks absolutely fine?

Also who supplies replacement these drivers?

Cheers

Andy
 
Hi Andrew
Visually they look fine, but are damaged internally. As for availability, any of the electronic component companies will sell them. Where are you based? There's often someone local who can help out with this kind of thing.
 
Also, and I may be wrong, a good test for this is removing the switch plugs from the cpu board. If the fault persists, you have a board fault.
 
Hey, I’m in Portishead, Bristol. Just had a google search looks like they’re easily available. Am I right in thinking some people will add a socket so they are easily replaceable in the future?

If so are these also generic and available from an electrical wholesaler?
 
Also, and I may be wrong, a good test for this is removing the switch plugs from the cpu board. If the fault persists, you have a board fault.
Yes I think I tried this correctly and problem persisted. So by board problem do you mean this 2803a driver? :D thanks so much for the help
 
Don’t just go off what someone posts on here u20 is worst case thing really disconnect the playfield switch wires from the cpu and see if the problem still then at least you can narrow it down to the cpu or playfield and do the same with the cab
 
So I’ve turned it on with j212 j206 j208 j205 unplugged and it says the same error message.

Is there any other way I can diagnose this?
 
This is the exact same fault that @Calimori had on his TAF some years ago and @Sgt GrizZ is spot on
The ULN 2803 is not a very robust chip and fails internally very easily it can also take out one or more of the LM339 chips
if you find after replacing U20 that a switch or test button will not work then its quite possible this has happened.
 
So based on that it looks like a cpu board issue.
You're right, when removing these chips it's best to replace with a socket, then add the chip. The boards can be fragile and by adding a chip you're making sure that future replacements don't need soldering.
If you're confident at soldering it's not too tricky to replace. If you arent confident it's not the ideal thing to learn on.
 
You can replace the chip but you still need to find the short that caused it to blow in the first place. Typical cause is something loose or shorting on the flippers, eos, etc.
 
So it’s been a while...... I’ve got a bit further but not far.....

I replaced he uln2803a on the MPU board....

The fault stayed....

I got a pinball repair man round, he diagnosed that there was a fault on the main driver board, and one if the 12v supplies was not working right (mainly the supply to the MPU board, hence the apparent ground short row 1 fault), it was suggested a newrottendog driver board would Be better than repairing the old board

So I’ve replaced the old driver board with new rotten dog board

Fault has now changed to check fuse f114 and f115

Menu buttons still do not work...

I’m stuck again

Still no pinball since January.

Any help much appreciated.

X
 
Hello, Andrew,

During all this time, has the Door Interface Board, near the tilt inside the left wall of the cabinet, been disconnected? The message about those fuses appears if a Test 'switch' isn't seen as Closed by the program; I think the intention was to detect a lack of the 12v source used for the switch matrix. It isn't actually a switch as such, but a diode connecting the relevant lines of the switch matrix (Column 2 and Row 4) on this board. The wiring from the interface to the mpu being detached at either end would bring up the message
 
Hello, Andrew,

During all this time, has the Door Interface Board, near the tilt inside the left wall of the cabinet, been disconnected? The message about those fuses appears if a Test 'switch' isn't seen as Closed by the program; I think the intention was to detect a lack of the 12v source used for the switch matrix. It isn't actually a switch as such, but a diode connecting the relevant lines of the switch matrix (Column 2 and Row 4) on this board. The wiring from the interface to the mpu being detached at either end would bring up the message

Don’t think so.... here’s a pic
 

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Here’s my 2 boards, still check fuse 114 115 which are fine. Menu buttons don’t work, all lamps come on, bookcase turns on power on.

Maybe I try a new cpu board now?

#expensivefaultfindingsofar!
 

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Have I got all the connectors on the MPU board in the right place? Just in case after taking it in and out I’ve done it wrong!
 

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Looks ok to me
I think your best bet is give jim@mypinballs an e mail send him the cpu and both driver boards to test and repair
I don’t agree with you Pinball guys diagnosis as the 12v being low I have never seen that be a short to ground fault and also is a simple repair no need for a new driver board
The quality of reproduction boards particularly rotten dog ones is no where near as good as the original Williams ones
 
Hi Chris, thanks for the great advice, feel a bit gutted I’ve forked out £300 for a new driver board ....

I’ll contact jim and see how I get on.
 
Yes a bit of a bummer but I don’t think the shot gun approach is the way to go just trying people hunches is not getting you anywhere probably making things worse jim can test and repair the boards at least then you have peace of mind and a solid start to if there is anything else wrong my guess is maybe battery damage on cpu but does look ok on pic
 
I think I’m happy to send those 2 boards off for full repair, I suppose then I can use the rotten dog as the everyday board to get smashed, I’m NEVER going to sell the Addams as it’s my first and already totally in love for years to come for all the family, so having my original as a spare is not going to be a bad thing?


I’ll email jim tomorrow and start the ball rolling.

Thanks so far guys

X
 
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