Download the manual over at ipdb.org. Go to the schematics in the back. I think somewhere in there it will tell you the voltage values you should be reading at the IDC pins on the DMD. Verify you are getting those values and let us know what you find!

You will need to check the correct voltages are being sent to the display. Plenty of troubleshooting information to walk you through it here: http://pinwiki.com/wiki/index.php?title=Williams_WPC#Testing_DMD_Controller_Power

Start by taking your meter and setting the selector to Voltage (DC). Then place the black lead of the meter firmly under the braided wire in the backbox (Ground) or use alligator clips to make a secure connection to the braided wire. You now have ground on the black wire.

Now go to the back of the dmd display, and measure the voltages on the pins where the cable from J604 on the display driver board is attached.

Place the red lead on pin 1 (Orange), and write down the value measured (Should be very close to -125 V or -112V)
Place the red lead on pin 2 (Blue), and write down the value measured (Should be very close to -113 V or -100 V)
Place the red lead on pin 6 (Gray), and write down the value measured (Should be very close to +5 V)
Place the red lead on pin 7 (Gray/Yellow), and write down the value measured (Should very be close to +12 V)
Place the red lead on pin 8 (Brown), and write down the value measured (Should be very close to +62 V)

NOTE: If -125 is measured on pin 1, Pin 2 needs to measure about -113. But if -112 is measured on Pin 1, Pin 2 needs to measure about -100. The important thing here is that the difference between Pin 1 and 2 is 12VDC.

I bet one or more of the voltages are way off or missing. But report back with your measurements... It could very easily be one of the "big white" resistors on the display driver board.

Display voltages (resized).png

It appears you're unfamiliar with using a meter. Please be careful as the voltages produced foe the DMD are not trivial... over 100 volts DC. Also be very precise with your meter lead olacement. If you still have IDC connectors (the kind where the wire is pushed in from the top) then keep the connector on and test by pushing your meter lead into the top...you should be able to touch the wire blades that make contact with the wires. Much easier and much safer than trying to put your lead on a header pin. One slip and you bridge two pins with your lead and cause more damage than you already have.

Yes, DC....Time to check your AC incoming and your fuses.

https://www.ipdb.org/files/20/Bally_1992_The_Addams_Family_Manual.pdf

Goto page 3-20 (PDF page 122). Check all those voltages. Check fuses F601 and F602 on DMD Controller.

Note: For AC, put your Red and Black leads across both that say 80V and then 100V. Do not keep your black lead on ground.

http://www.arcadeshop.com/i/989/williams-bally-wpc-wpc-s-dot-matrix-controller-board.htm

They seem to be back in stock if you decide to go this route.

Good resource to have. In this case, the OP swapped DMD boards to no effect. This looks to be a voltage issue.

Is the plug in the bottom of the cabinet plugged in? It’s the purple wires

I have had it unplugged before and that caused that issue

No, the plug is for the AC voltage from the transformer. If you're reading AC then that's ok.

Did you check the two fuses? These feed the Bridge Rectifiers on the board to convert the AC to DC through BR1 and BR2.

If the fuses are OK, set you meter to DC, and check across the capacitors C4 and C7, then R12 and R13.

Note: I'm going by a WPC Schematic for BSD (I have a printed set) which should be similar, but if you note any inconsistencies in the device numbers, let me know.

I see all kinds of cracked solder joints on those transistors. You'll need to clean and use flux for them to accept solder. Many times, that's it. Also, looks like your're missing a chip there . For the money, just throw in a new DMD controller.... this one is a little crispy

Could be a possibility too, but that boards nowhere near crispy....every HV section on a WPC looks like that And no, no chip missing....U12 isn't used.

Most of the time. Sometimes, very rarely, the fuse is just old and a small spike in voltage takes a fuse out (we are talking years-old fuses). If you put a new fuse in, and it blows within the week, something isn't right.

Br1 and c4 are next in line. Either can short...if the caps look original id replace them. The BRs are the IC style and rarely go. You can rebuild the HV section for about $30 in parts if you're handy with a solder iron. I just did one last week.

Desolder 1 leg and test with a meter. If you don't have a meter that can measure capacitance you're only going to be able to test if it's not all bad

https://www.ifixit.com/Wiki/Troubleshhoting_logic_board_components

Scroll down to testing

No problem....if you decide to rebuild the HV section, here's the parts list. Ed at GPE doesn't assemble the kits anymore, but you can order all the components separately from his site.

https://www.greatplainselectronics.com/proddetail.asp?prod=WPC-HVP-KIT

Be sure to get the optional filter caps C4 and C7.

High Voltage repair kits...

http://LockWhenLit.com/products.htm

Although on the lesser end of soldering skill level, installing the kit shouldn't be attempted unless you're completely confident in your ability to do it correctly.

--
Rob Anthony
Pinball Classics
http://LockWhenLit.com
Quality Board Work - In Home Service
borygard at gmail dot com

Not to overcomplicate things, just a polite piece of advice. If this comes down to desoldering and soldering new pieces in, a desoldering gun should be used to minimize board damage (lifting traces).

Best to either work on a spare board and ensure you know how to properly use a desolder gun, or send it to a professional like Rob (above) or Chris Hibler who both are well qualified to do the job right.

Again, not trying to discourage DIY work, more like issuing friendly advice and make sure your skill sets are ready to do this.

Another option is to buy the Rottendog board as Phat_Jay suggested earlier and sell your old board off for rebuild and keep it alive in the community.

https://www.pinballlife.com/williamsbally-dmd-high-power-replacement-board.html

Good Advice....I've been soldering for 20+ years, and I just recently bought a nice desoldering station. Makes life SOOOOOO much easier. Right tool for the job. I used to use the plunger suckers or solder tape, and can't tell you how many times I had to fix my own repairs. Now, I'm pretty confident in tackling any job.

Rob,

Somehow need to get your site into google searches. I literally started a thread a few weeks ago about who sold the kits anymore, since I knew Ed stopped. Crickets, and not once did your site come up under my google searches. Would have considered buying the kit from you had I known!

Very niche market and most that are qualified are normally backed up in orders. Another name would be very well welcomed into this community.

Actually - I didn't stop selling these kits but don't get much time to make more kits. I did list 100 of them when I reopened on January 7th. 100th kit was sold on the 21st. When will I be able to make more? No idea...

Ed

Wow....100 kits in 14 days. Apologies Ed...from your post a few weeks ago about your other job keeping you long hours that you don't have time to make kits anymore and you thought about removing the links, I incorrectly assumed that was a permanent decision.

Put in a ColorDmd and unhook that board

Shit. That's a fantastic idea!! Looking at your collection, $400 should be couch cushion change to make this problem go away!

Possible. What brand is the DMD? Make sure you are testing resistance with the DMD power connector unplugged. I can see if I have the same brand DMD to compare to.

62 v section shorted on DMD (resized).jpgI just measured a good babcock DMD and my 62v pin to ground measures 3 meg ohm. That 100 ohm tells me there is either shorted 2 diodes/2 transistors and/or one or more of the 4 ICs for the columns shorted. I had just repaired one a year ago that had this problem with the parts mentioned.

Oddly enough, the Babcock, Chetry and Vishay DMD schematics are in pretty much in every DE game manual.

Working on our STTNG and recorded the difference between pin 1 and pin 2 to be 21.7v not 12.8 as stated above. All other values in range. Anyone know a next step to debug this ? Replacing a cracked screen with a know good one and we still have no images on the DMD. All fused and connectors checked and good.

Thanks!