Author Topic: Wanted: Outgassed Dot Matrix pinball display (Read 11908 times)

2PacMan · « **on:** May 07, 2007, 08:26:14 am »

I was wondering if anyone had an outgassed Dot Matrix display for pinball games. I bought a pinball and my DMD is completely dead. I have no other DMDs to test this with. So I was hoping someone might have an old useless DMD that shows some slight activity that I can plug in to see if I do indeed need a new DMD or if it is something else causing the problem. I could even ship it back to you if you wanted it back, I just need it for testing. Thanks!

ChadTower · « **Reply #1 on:** May 07, 2007, 08:59:10 am »

I keep one around for just that reason... I'm sure on RGP you can pick one up cheap. I'd ship you mine but they ship very poorly.

What pin is it? How are you sure it's the DMD? DMD driver boards are common failures.

2PacMan · « **Reply #2 on:** May 07, 2007, 09:45:05 am »

It is a Gottlieb Super Mario pinball. It's the first (and probably only) DMD machine i've ever owned. The guy I was buying it from said it worked 100%. I drove 100 mi to meet him to pick up the game, when we got there, the DMD was not working. He said "it looks like it just needs a new DMD, i'll knock some $$ off my price so you can buy a new one, they run about $130.00." I couldn't really leave empty handed after driving for so long, so we agreed on a new price.

I just wanted to make sure it really is a bad DMD before I shell out 130.00 ordering a new one. I was reading on marvin's site that it's possible it could be the DMD driver board, as they cause problems as well. I would be in over my head when it comes to fixing those, and would probably have a tech come out if that is indeed the problem. I don't notice any burned areas on the driver board. The DMD is just completely black, no signs of life at all. But the LED lights on all the circuit boards inside the head flash and communicate normally.

Is it common for a DMD to be completely burned out by now? I think the game was made in 1992. Thanks for your help/advice Chadtower.

ChadTower · « **Reply #3 on:** May 07, 2007, 09:51:13 am »

DMDs can be burned out by now, the DMD could be dead, any of the connectors in the line could be loose from moving it, the fuse could be blown... if you just moved it like that, it's not a good idea at all to buy a new DMD yet. Start running through all of the trouble shooting steps at marvin3m for that boardset. Reseat the connectors, check the fuse, whip out your DMM and check the DMD driver board test points for proper voltages (marvin3m will tell you exactly what they should be).

2PacMan · « **Reply #4 on:** May 07, 2007, 09:53:45 am »

Thanks Chad....is there anything to look for on my old DMD to see if it's dead or not? Like is there some kind of continuity test I can perform on it? I reseated the connectors to the DMD board itself with no luck. I haven't tried reseating all the connectors throughout the pinball though.

ChadTower · « **Reply #5 on:** May 07, 2007, 09:56:41 am »

Look up the DMD driver test point voltages and test those. See if your board is getting proper levels. That will tell you instantly where the problem is likely to be.

Do you have a DMM and know how to use it?

2PacMan · « **Reply #6 on:** May 07, 2007, 10:10:08 am »

I have one, but don't really know how to use it. I've done continuity tests with it, but that's about it. When we were picking up the pin, he did continuity tests on all the fuses, and they all checked out, so i've ruled that out at least. I'm not even sure what settings to put it on or where to stick the probes when it comes to measuring voltages on a board.

ChadTower · « **Reply #7 on:** May 07, 2007, 10:21:47 am »

If you're going to get into pins, you need to learn to do this anyway, so let's get on it.

Dammit, my work proxy has blocked Marvin3m's site, so I can't look up the voltages and help you along. Go to the Gottlieb section for your pin, I think it's System80 but double check that. It will have a very detailed description of checking the DMD driver board test points.

Also, look in your manual, and learn how to set your DMM to test AC and DC voltages. You're very likely going to have to be testing DC voltages here, 3-4 different values. All it is is putting your DMM in the right mode, putting one lead on a test point, and the other lead on any ground point, then looking at the value displayed. There is no danger in getting the leads reversed as all that will happen is your value will be displayed as negative instead of positive.

shardian · « **Reply #8 on:** May 07, 2007, 10:33:53 am »

Quote from: ChadTower on May 07, 2007, 10:21:47 am

Dammit, my work proxy has blocked Marvin3m's site, so I can't look up the voltages and help you along. Go to the Gottlieb section for your pin, I think it's System80 but double check that. It will have a very detailed description of checking the DMD driver board test points.

http://www.the-cloak.com/login.html

Try that. I used it back when I worked for Corps of Engineers to access my webmail.

ChadTower · « **Reply #9 on:** May 07, 2007, 10:35:50 am »

Also blocked. $:-\$

2PacMan · « **Reply #10 on:** May 07, 2007, 10:45:24 am »

OK, i'm on marvin's site now. It looks like Super Mario is a System3 game. Looks like I need to be looking at the DMD controller board. I'm reading up on it now. It says if you change the DMD with the power on, it could blow one of the transistors in the high voltage section of the board. I guess this could be a possibility.

ChadTower · « **Reply #11 on:** May 07, 2007, 10:55:03 am »

At this point, anything on there could be a possibility. Recheck continuity on the fuses, old ones can break when jostled.

The place to start is the DMD controller board test points. That will tell you where your next steps are going to be.

I have printed copies of the marvin3m pages at home... I guess worst case scenario is I bring them in tomorrow.

2PacMan · « **Reply #12 on:** May 07, 2007, 11:02:03 am »

OK...i'm at work right now, so this might be a little difficult as i'll probably get your advice during the day, and in the evening go home and try things and report back to you tomorrow morning.

Just to be sure, there is no way I can screw anything up by sticking the DMM probes all over the board, right? I mean, just in case i reverse the probes or stick them in the wrong place, i can't damage anything, can I? Other than the DMD, the machine seems to be working fine, and i just don't want to chance that I could make it worse.

ChadTower · « **Reply #13 on:** May 07, 2007, 11:07:20 am »

Probably not on the DMD driver board. Don't go jabbing it into straight AC places or anything while in the wrong mode, you could blow your DMM's fuse. On that particular board we're not talking about enough amps to be a problem, I think.

Just be careful not to short anything. A common way to do that is to try measuring two very close items and ending up touching the probes together, creating a bridge, and therefore shorting them out.

Test points are usually obvious. They're metal loops raised up from the PCB and don't look like components. They look more like mounting holes and are usually labeled with what they are for (i.e. 5v, 12v, 125v, etc).

2PacMan · « **Reply #14 on:** May 07, 2007, 11:27:05 am »

OK, i can measure these tonight if they are clearly labeled. I stick the red probe into the raised metal loop, but where do i stick the black probe? And should I have it set on DC? Thanks Chad.

ChadTower · « **Reply #15 on:** May 07, 2007, 11:29:28 am »

I would think it would be DC, but that's an educated guess, you'll have to check the marvin3m guide for exactly what should be there. I would anticipate having to check either 3 or 4 different voltages. The black probe you would put on some ground point, the guide will probably point you to a convenient one on the board, if there isn't a test point labeled GND.

2PacMan · « **Reply #16 on:** May 07, 2007, 11:48:55 am »

A dumb question, but just double checking....i need to have the game on to do all these tests, right?

ChadTower · « **Reply #17 on:** May 07, 2007, 11:50:47 am »

Yep. With the DMD connected, probably, as the potential load of the screen will affect your readings. That should be laid out in the guide.

ChadTower · « **Reply #18 on:** May 07, 2007, 12:41:07 pm »

One on ebay.

ChadTower · « **Reply #19 on:** May 07, 2007, 02:10:23 pm »

I'm still poking around for some resources for you... try this to learn about your DMM.

2PacMan · « **Reply #20 on:** May 07, 2007, 02:23:21 pm »

Great page, Chad thanks! I won't be able to poke around the machine until i get off of work tonight. I'll report my findings first thing tomorrow morning. Hopefully I can get some useful information that we can use to diagnose the problem.

2PacMan · « **Reply #21 on:** May 08, 2007, 08:18:18 am »

OK, Chad, had a chance to look at things last night, and it doesn't look good. I couldn't find any places to measure voltage, but there is a burn spot up in the high voltage area of the DMD driver board. So it looks like my board is bad now. Now what do I do? Do they sell replacements? It looks like a few chips on there are labelled specifically for Super Mario. Here are some pictures. The first is the burned area, the second is the whole DMD board, the third is the entire backbox inside. Can someone repair this if i send it out? Does anyone do this sort of thing. I'm really bummed right now.

ChadTower · « **Reply #22 on:** May 08, 2007, 09:17:47 am »

Looks like the HV section of your DMD driver burned up, based on the blurry pics and description. That is common. You can rebuild it with one of these kits. I had to do the same rebuild on my Shadow and bought my kit from GPE, it was great. It is really hard to see the extent of possible damage to traces in that picture. This rebuild only requires moderate through hole soldering skills, plus the ability to find and repair burned traces if necessary.

Also, if you do it, evaluate the molex connectors and male header pins on that board. If either shows signs of heat damage, replace both parts. This is a good skill to learn for vids and almost necessary for pins.

If you don't have that skillset yet, it won't be hard to find someone willing to do that repair for you for a fee.

2PacMan · « **Reply #23 on:** May 08, 2007, 09:28:34 am »

Thanks Chad! That place is right in my backyard. I literally live about 5 minutes from GPE. I'll see if I can pick up a kit. What are those black U shaped things in the top corner of the board, i see there are 3 of them and one of them has alot of burn area around it. I don't see any of those in the replacement kit. Do I need to replace one of those too?

ChadTower · « **Reply #24 on:** May 08, 2007, 09:37:18 am »

I can't tell what you are referring to, the pic is too dark, and I don't have that schematic handy. Top right or top left?

2PacMan · « **Reply #25 on:** May 08, 2007, 09:41:44 am »

It's on the top right corner as you are looking at it. Here's a pic. It's a row of 3 black u-shaped components.

ChadTower · « **Reply #26 on:** May 08, 2007, 09:44:46 am »

I see the ones you're referring to but I can't ID them based on the pic. I'd look them up on a schematic/parts list. Do you have the manuals?

2PacMan · « **Reply #27 on:** May 08, 2007, 09:51:46 am »

No, it didn't come with manuals. I'm trying to get one off of ebay.

I know you've already helped me a ton, and i appreciate it, but would you be willing to fix my board if I get that kit and send you the board along with the kit? I'd pay you of course. Or would it be better to find someone local?

ChadTower · « **Reply #28 on:** May 08, 2007, 09:54:28 am »

I would be if I had a way to test it. I don't have a Sys3 pin.

If you use torrents, there is usually a torrent or two out there that is like 4gig of pin manuals. It's worth a search. I probably have that manual on DVD at home and can try to find it tonight if you want, though I haven't accessed it in like a year and am not sure where it is right now.

2PacMan · « **Reply #29 on:** May 08, 2007, 10:00:40 am »

Thanks Chad. In all honesty, even having the manual probably wouldn't help me much. I don't know how to read schematics or anything. The only soldering i've done is wires and buttons and solenoids, stuff like that. I've never done circuit board soldering, which i've always heard shouldn't be done unless you really know what you're doing.

Maybe at this point, I should just admit i'm over my head and try to find someone that can fix this for me. Since the guy knocked some money off the price of the pin, i do have a little cash to play with as far as the repairs go (assuming the DMD works once the driver board is fixed).

One other question. I tried to pull the driver board off the inside of the head of the pinball to view the backside, and it's stuck on by white plastic tabs of some sort and i can't get it off. Is there a trick to it, or do you just pull real hard?

ChadTower · « **Reply #30 on:** May 08, 2007, 10:09:50 am »

The PCB holders are probably the same type you would see holding a motherboard inside a PC case. There would be some type of flexible tabs that if pushed in would allow you to slide the hole off the holder. Don't flex the board too hard, they're not made to be bent.

This isn't too hard a job for a first PCB work if you want to take time and be careful with it. The components are big and spaced well. Grab some old junk boards (ancient PCs are great for this) and learn to desolder components with a solder sucker. It shouldn't take that long to get the hang of it and of course there are tons of guys who can advise here. Guys here and at RGP helped me learn to solder.

Of course, there's also no shame in finding a place that will do it for you, as this is a common failure and probably won't cost that much to have someone do for you. I'd do it for a 6 pack if I had some way to test it here.

EDIT: BTW, did you read through the marvin3m section on testing those voltages? Just being dark doesn't necessarily mean it's burned up. The HV section attracts a lot more dust as it has a higher static field. I didn't look last night but I'd be shocked if marvin3m doesn't tell you exactly what to use for test points.

2PacMan · « **Reply #31 on:** May 08, 2007, 10:26:56 am »

I didn't see anything about test points on Marvin's site. Its almost like he just brushed over that secion. He talked about how changing the DMD with the power on can fry the board, and showed pics of a fried board. And then he said there was a chip that can go bad in that section that can cause garbled messages on the DMD board, but that's it really that I could see.

I really need to see if there's someone local here that has a DMD pin that i could just throw my display in, that way i could totally rule that out as being the culprit.

SirPeale · « **Reply #32 on:** May 08, 2007, 10:27:10 am »

With a pin that old, it wouldn't surprise me at all if the display just completely died.

One of the last pins I worked on came into the shop with a crappy display. I literally turned off the machine, plugged in a known-good used display to test it, but hooked the old one back up as I was going to get to it later. It did nothing at all.

But you definitely have heat damage on that board. Likely the components are okay, but you need to resolder the joints. That entails removing the old solder and resoldering, not just topping it off.

ChadTower · « **Reply #33 on:** May 08, 2007, 10:35:09 am »

Yeah, it's definitely possible that the DMD is dead. We want to rule out the cheaper solutions first before he drops $100+ on a new one. The DMD rebuild, if he can do it himself, is a worthwhile refurb job anyway.

I guess in the short term, get some alcohol and clean up that section of the board, so we can see how much of that is grime and how much is heat damage.

2PacMan, I sent out a couple emails around here to guys I know who may have a Sys3 to test in and may be willing to do the rebuild.

2PacMan · « **Reply #34 on:** May 08, 2007, 10:45:30 am »

(About the emails) thank you very much Chad. Hopefully someone can do it.

One more question for you. Is there any harm in continuing to play the game? I've been playing it the last few night with the nonworking DMD hooked up. Am I further damaging anything by doing this? Should I just leave it alone until everything is fixed?

ChadTower · « **Reply #35 on:** May 08, 2007, 10:48:03 am »

I'd disconnect it, myself.

2PacMan · « **Reply #36 on:** May 08, 2007, 11:08:10 am »

Just disconnect the DMD and continue to play it, or just stop playing the whole thing until it's fixed?

ChadTower · « **Reply #37 on:** May 08, 2007, 11:09:47 am »

Disconnect the DMD.

None of the local guys I'd recommend for mail order work seem to have a Sys3 on hand to test with. Damn.

2PacMan · « **Reply #38 on:** May 08, 2007, 11:22:58 am »

Well, thanks for trying. There's a local place here that's in "the business", maybe I can take it there. I'll probably pay more for the repair, but at this point, it might be my only choice.

ChadTower · « **Reply #39 on:** May 08, 2007, 11:23:31 am »

More for the repair, less for shipping.


Main	Restorations	Software	Audio/Jukebox/MP3	Everything Else	Buy/Sell/Trade
Project Announcements	Monitor/Video	GroovyMAME	Merit/JVL Touchscreen	Meet Up	Retail Vendors
Driving & Racing	Woodworking	Software Support Forums	Consoles	Project Arcade	Reviews
Automated Projects	Artwork	Frontend Support Forums	Pinball	Forum Discussion	Old Boards
Raspberry Pi & Dev Board	controls.dat	Linux	Miscellaneous Arcade	Wiki Discussion	Old Archives
Lightguns	Arcade1Up	Try the site in https mode		Site News


Unread posts \| New Replies \| Recent posts \| Rules \| Chatroom \| Wiki \| File Repository \| RSS \| Submit news