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Williams DMD showing gibberish :(

lozpeters

lozpeters

Registered
10 Years
Joined
Jan 3, 2013
Messages
133
Location
Bristol
Hey guys, hopefully someone an help :)

I have a Flintstones that was working fine until a few weeks ago when i had it on all day for a party and i have just got around to having a look

20180610_193949.jpg

When i turn it on the DMD just shows gibberish, the machine boots up fine and will start a game. I have reset the ribbon cable a few times & flipped it, i dont have another one to check but i did use the multimeter to check continuity down he wires and it seems to check out ok. I re-seated the chips and connectors on the CPU, soundboard & DMD driver & still no no change

Checked the voltages at the DMD and get (both connected and disconnected)

-120.1v
-96.5v

4.9v
12.3v
65.5v

These voltages got up to these numbers after about 2 mins of being on rising about 2 -3v in this time. The driver board looks like it has been rebuilt in the past so maybe it is this?

Before i rebuild the driver again or get a new DMD is there any other suggestions on what to try??

Or is there anyone in Bristol (i am in Fishponds) who has a machine i could test out my DMD & driverboard in?

cheers
Loz
 
Yeah repeated ribbons multiple times but with no luck.

Just seen in the flipperwinkle that the voltages should be -125v and -113v. I was looking for -112v & -100v from another repair guide so maybe mine are much lower then they should be
 
I'm in Newport and have a Getaway we could try them on. Have you run the DMD test? it will tell you if you have any memory faults on the driver board ( you did say it was displaying gibberish, not just faded/gasing etc )
 
Knackered after glasgow but iirc ya want about 12v difference give or take,which ties in with those other figures you mentioned.Rebuild kits for dmd driver are available as are boards
Or just fit a colordmd?
 
Last edited:
Clean the pins of both sides with isopropyl alcohol and cotton buds. Unless you've done this before to electrical contacts you will absolutely not believe just how much oxidation - and dirt - you can lift off seemingly clean pins. Yes, pins can spontaneously fail while in-use after being fine for X amount of time.

If you can't supply IPA then if you really have to - scrub the pins carefully with just the cotton buds - or paper towel. You'll need to exercise caution as you could easily bend pins if you're doing it right.

It's certainly something I would rule out before rebuilding the boards. I've got a number of projects on the go ranging from a pin, to a Neo Geo, to the old family Megadrive/N64 systems, and even my brother's desktop computer - and they ALL have had a serious issue sorted by a chemical clean on at least one connector.

I was on here recently about a Black Rose machine that had two coils just totally fail on me - reseating some ribbons caused garbage on the DMD, and caused coils to lock on on startup blowing fuses. All this required to restore to full working order was some of the neat stuff.
 
Still no luck :( I got a hv rebuild kit and fitted all the parts and the display still shows the same gibberish :(

Anyone in Bristol that I could test the dmd on their machine??
 
lozpeters said:
Yeah that's what ime thinking but supposed to be saving for our wedding so will have to work out funds :)
Click to expand...
@DrPinball has a very nice replacement dmd and you get to choose a range of colours, yellow would look good with Flintstones, if the fault is with the HV then it doesn't matter as this comes with its own power supply.
 
Power for the colour DMD is taking from J116. If J116 is in use, included is a male to male connector. Color DMD's are expensive but defo best mod, upgrading speakers is probably next best.
 
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