DMD Row 9 is out

I'm troubleshooting my first DMD display. (I counted down from the top, 1,2,3,4,5...8) then the 9th one is out.

Looking for guidance on how to troubleshoot and resolve.

Looking for best topics in Pinside to review and online resources to review.

At first it was an intermittent problem (10-20 plays ago), and now it's rather consistent.

Game is Getaway.

1. I've reseated the ribbon cable on both ends.
2. I've reseated the other cable on the DMD end -- didn't see yet where to reseat it on the MPU end

Thanks!
-mof

#2 8 years ago

BAD

Brtlkat

Pinside member

Fort Pierce, FL

11y 52,050 1,511 14

Hard to fix lines out in a dmd, I would Start looking for a new one.

#3 8 years ago

BAD

Brtlkat

Pinside member

Fort Pierce, FL

11y 52,050 1,511 14

Hmmmmm You have 6796 post, One would think you would have read about these on here already.

#4 8 years ago

TAB

terryb

Inactive member

https://pinside.com/pinball/forum/topic/fixing-a-dead-dmd-column-or-row-cherry-4205-dmd#post-322440

If you're missing a single line the vast majority of the time it's a break in the connection at the glass.

#5 8 years ago

MOF

mof

Quoted from terryb:
If you're missing a single line the vast majority of the time it's a break in the connection at the glass.
https://pinside.com/pinball/forum/topic/fixing-a-dead-dmd-column-or-row-cherry-4205-dmd#post-322440

Thanks Terry. I wonder how I can test for this. I don't happen to have an extra DMD here. I can see the value in having a working backup.

-mof

#6 8 years ago

TAB

terryb

Inactive member

Take something pointed and non-conductive and push in on the area where the connection is while the game is on.

#7 8 years ago

MOF

mof

Quoted from terryb:
Take something pointed and non-conductive and push in on the area where the connection is while the game is on.

Sounds good. What's a good tool -- seems like a bamboo toothpick is too wide.

-mof

#8 8 years ago

TAB

terryb

Inactive member

I use orangewood sticks (I've covered these in my soldering guide) or you could fashion something out of a wooden skewer.

3 weeks later

#9 8 years ago

MOF

mof

I was able to get a plastic tool and push in there -- I saw row 9 turn on a bit -- so I'm more convinced it's that connection.

-mof

#10 8 years ago

MAO

MikeO

Pinside member

Overland Park, KS

11y 88,400 3,625 41

The recommended solution applies if the DMD glass is a pin style as shown in the referenced tutorial.

If it is the ribbon connection style you are generally SOL.

#11 8 years ago

MOF

mof

Here's my Cherry DMD:

I put a temp sharpie mark on pin 9.

-mof

201510_Get-cherry2.jpg

201510_Get-cherry1.jpg

#12 8 years ago

TAB

terryb

Inactive member

The pin you have marked slides between two sheets of glass (at the top after the 90 degree bend) and presses against a copper pad. You will need to expose the copper pad and then epoxy the pin to the pad.

3 months later

#13 8 years ago

MOF

mof

Ok, I'm going in...
-mof

Cuts have been made. Pin from board is definitely loose.
-mof

20160214_214516_(resized).jpg

#14 8 years ago

MOF

mof

New "L" shaped wire made. (3/8" by 1/4") Time to solder it in place.
-mof

20160214_223002_(resized).jpg

#15 8 years ago

MOF

mof

I've lathered on conductive epoxy, in the hopes that will minimize vibrations and hold a good connection.
-mof

20160214_233127_(resized).jpg

#16 8 years ago

MOF

mof

It works!
It sure took a while, but it was a fun fix. I hope it holds!
Now to cure the epoxy at 149F for 60 minutes...
-mof

#17 8 years ago

TAB

terryb

Inactive member

OP
Quoted from mof:
It works!
It sure took a while, but it was a fun fix. I hope it holds!
Now to cure the epoxy at 149F for 60 minutes...
-mof

Congratulations. That's a delicate repair.

#18 8 years ago

DEL

SealClubber

Pinside Moderator

14y 127K 11,060 246

Man that is ugly. But effective and a whole lot cheaper than replacement. I like that in a repair.

#19 8 years ago

MOF

mof

Meh, I didn't get enough conductive epoxy underneath the wire, and it must have come loose. I'll give it another shot another day. It is most definitely not a job for an unsteady hand. Difficulty: 9/10.
It *was* working...
-mof

1 year later

#20 6 years ago

STF

UltraPeepi

Pinside member

7y 44,900 223

I just repaired my Theatre of Magic dead columns using the threads I found here. I didn't drill. I bought a set of dremel glass cutting wheels. The drill is probably the way to go. If I did it again, with the dremel wheel, I'd probably go at it from the side to try to expose the tab. It doesn't take much to contact with the conductive paint. BTW, mine doesn't look like the ones above - but the fix is the same.

Dremmel wheel ($10) - https://www.amazon.com/gp/product/B016NTYAJI/ref=oh_aui_detailpage_o07_s00
Conductive paint ($15) - https://www.amazon.com/gp/product/B01M28SRH0/ref=oh_aui_detailpage_o04_s00
Ultra fine paint brush ($4) - local craft store

So basically $30. Given that I saw some used DMDs at the local pinball & arcade swap meet for $90, and the difficulty of the repair, I'm not sure I'd recommend the fix.

I'd say it's a difficulty 8/10.

#21 6 years ago

TAB

terryb

Inactive member

Congrats on getting it working. It is a very delicate job.

#22 6 years ago

JRP

Gogojohnnyquack

Pinside+ Frequent

Seattle, WA

9y 84,300 1,361 5

Quoted from UltraPeepi:
I just repaired my Theatre of Magic dead columns using the threads I found here. I didn't drill. I bought a set of dremel glass cutting wheels.

Congrats. This is a scary repair to start. Got any pics?

1 month later

#23 6 years ago

MOF

mof