Probably one of the most common problems people experience with the modern Bally/Williams DMD machines are random resets of the game in progress. Sometimes it appears these resets happen at certain times (like when you hit a flipper or during multiball) and you think it may be directly related to that. Most of the time, that’s not the case, although heavy activity like firing certain solenoids might cause a drain which exposes a weakness in the game’s power system. We’re going to go over the standard procedure to deal with this issue.
After the board is removed, I go over the process to desolder and remove components.
Now time to solder the new components on the board. You have to be very careful to not mess up the traces. There are also some recommended jumpers you can run around the bridge rectifiers to double-up on the traces. I don’t go into that in the video but you can look at Clay’s guide for more details on that.
Another thing you might want to do if you do not replace all the caps, is to mark on the top of the cap the month/year you replaced them. This way in case there’s any confusion, you’ll know which components are newer and which ones may still be original.
And now the moment of truth!
I own a mr/mrs PAC man worked great is refurbished lights come on but it won’t start. Any suggestions?
There’s not enough to go on to diagnose things, but I’d check the MPU board to make sure it’s ok – if there’s battery damage, the best bet would be to replace that with a new mpu board if you’re not comfortable making board repairs yourself.
the header pins go bad,did all that crap still would reset.changed the head connectors on the mpu board,and the sdu.all the problems disappeared.
who would think a solid piece of metal would fail for a pin.
I have seen it myself. Intermittent contact does that.
First off, thanks so much for these videos. Frankly, I like your method of just straight shooting the video without edits; some of the slip-ups can make the good information easier to understand.
Now, on to the important question: how did you know to only replace 2 caps and 2 rectifiers? I’m having these reset issues on an Addams Family pin, and upon visual inspection, I don’t see any glaring issues with any of those components. Seeing as there are 4 rectifiers and 4 caps that match in that area, my gut tells me to swap the lot, but if just those 2 of each, along with the linear cap, are sufficient, that’s great.
Just to clarify, I have already checked my line voltage at the wall. Lowest has been 119, but it’s typically between 120.5 and 122. I’m pretty sure the rectifier/capacitor swap is my next step.
It’s not a bad idea to replace all the BRs but the caps are usually the culprit, but some of the circuits in the game take more stress than others and those BRs heat up more.
Well, I popped the power driver board off, and figured I’d post back what I found…
BR3 had very obviously been previously monkeyed with. Flux everywhere, cold solder joints on 3 legs, and the 4th leg, while the solder joint was good, had the upper trace lifted WAY off the board. I cleaned up the solder joints, and that alone fixed 95% of the resets. Turns out the remainder of the resets were due to the thermistor in the power box. Got a replacement for that on the way.
Thanks again for these videos 🙂
The Purists are going to hate me but I truly despise Williams power supply. So I leave the old one in there and wire in an SMPS that can tolerate 100 to 240 VAC input. It is not a great idea to connect the output of 2 DC supplies together in parallel so the old analog stays intact charged it just does not have a load on it.
Hi I have a wpc from a 93 judge dredd . There are two light circuits that form part of the missions that are currently failing j133. 8 and nine I have tested the play field and traced the faulty back to no voltage from the above terminal numbers. Is it possible to be the transistors failing? Is there a common problem with the wpc controller. It is 20 years old.
I’d check the pins/connectors first.
Hello Thanks for your website . I have two pinballs one is a elvira and the other is a dr. dude they both have the same symptoms. when powerd up All the relays are running, plus all the lights try to light up and there is a loud hum thru the speakers. another common problem is f4 on the Aux power driver brd. blows. have you seen or exsperinced anything similar to this problem . any reply is welcome , thank you Wade W P.S. the game and display will not go into diagnostics
Blanking circuit is supposed to disable all lamp and solenoid drives until mpu is booted up.
May 2014 update: A new solution for resets is now available – a daughterboard that creates a 5 volt supply that drives only the MPU board. Check it out at http://www.kahr.us . No soldering required to install.
Hi Mike. I have exactly the same problem with my TOM.
Do you think it’s possible for you to give me the list of parts I need to change?
Thank you very much
I’m having the same reset issue with my Shadow pin. Would you mind listing the part numbers you used in your video and where you bought them. I would like to follow your steps but I’m not exactly sure what or where to buy them. Sorry I’m a newbie.
Thank you for this great video series.
It’s not so much part numbers as it is component specs. I like to order parts from Newark, but you can get pinball-specific electronic parts from Great Plains Electronics. Go by the rating of the part (i.e. 10k uf, 25v, etc.) You can read the specs off the existing components, or get them from the schematics on your pinball machine.
Also, before you go changing board components, also check your connectors – many cases of resets are bad pins and connectors.
What is the desolder gun that you used to remove the components?
The Hakko 808. I believe that model has been discontinued and there’s a newer version.