1. Installed new lcd Color DMD following instructions
2. As an initial test, routed Color DMD power cable outside of machine to the 5v/12v aux jack in the front-right of the machine
3. Booted up machine, Color DMD seemed to work (I saw high scores, etc)
3. Updated Color DMD to TSPP 4.1 ROM.
4. Went back to route Color DMD power cable properly through the cabinet. Also wiped down the playfield. Replugged it in to 5v/12v aux jack

After 4., it's not working properly and I'm getting various strange behaviors when booting up the machine. What I see most often:

1. turn on machine
2. "Stern Pinball Simpsons Pinball Party Display Version A5.00" appears on the DMD. At same time, TV on PF displays "TEST"
boot 01 (resized).jpg
3. After a few seconds, the DMD goes blank, and the TV on PF is still saying "TEST" (for longer than usual)
boot 02 (resized).jpg
4. After a few more seconds, DMD still blank, TV on PF goes into normal operation (it's scrolling "stern pinball" in below shot)
boot 03 (resized).jpg

Another thing that has happened once
1. Turn on machine
2. Color DMD is blank and TV on PF is all solid LEDs (I forget if Color DMD initially displayed "Stern Pinball Simpsons Pinball Party Display Version A5.00" prior to this)
2 (resized).jpg

I don't believe issue is with Color DMD itself. It displays. It's LED lights up as "DONE". I can go into the menu...
1 (resized).jpg

I've double/triple/quadruple checked pins on data cables are facing right way... here's what it looks like
3 (resized).jpg

Other things I've tried:
- reseating ROM on Display Controller Board (the original Stern one that's mounted to the Color DMD assembly)
- Reseating all ribbon cables in the backbox
- Reseating many of the power cables in the back box
- Checking/reseating connections to various cables in the cabinet where I routed the Color DMD power cable
- Tried a different 24-pin ribbon cable from CPU/Sound board to Display Controller Board
- Followed trouble shooting at Color DMD website (the only measure I didn't understand was "turn the game OFF and try reseating the blue 40-pin LVDS cable at both ends by lifting the pullbar and sliding the connector gently out of the socket." I don't find any 40-pin cables anywhere.)

I suspect something unrelated to Color DMD got messed up during the install, but I really don't know. It seems like the Display Controller Board is talking to the Color DMD given the initial ""Stern Pinball Simpsons Pinball Party Display Version A5.00" is displayed, but somehow data is not coming through right from the CPU/Sound board to Display Controller Board (I did try a different cable). I have not yet tried reinstalling the original DMD and seeing what happens, but I may do that.

Thanks for any assistance!

Yes, I set it to WS when installing. I just tried the original DMD and it's the same deal. Behaves still just as I describe above.

Thx,
Jack

Here's a video of the behavior I am seeing now (original DMD is temporarily hooked up).

https://www.dropbox.com/s/4evoipo77cmgj89/IMG_7914.MOV?dl=0

For the life of me, the only thing I can think of is the display controller board or CPU board is borked somehow.

Board looks okay visually. I’m not an expert with boards though. Rom is seated firmly. I did try reseating it. Here’s pics
1E28C9A6-C350-4904-9A3F-D7686559F5F5 (resized).jpeg333F12CC-F78B-415C-93D2-32DA923C688C (resized).jpegE5860247-B58D-490D-BDD6-E70B43D5A31B (resized).jpeg

As I said it was working before I started this, so that’s puzzling. But maybe the board got damaged somehow in the process. Thx for looking.

Thank you all for your ideas. 4.1 is the firmware version of the color DMD. I am running 5.0 game rom and display. Rom versions I doubt is the issue as I have reverted back to the original DMD (everything as it was when it was working) and getting the same issue.

northvibe I've tried three different 26-pin ribbon cables, reseating them, checked pin 1 direction, etc. I am really suspecting a board issue now. Unfortunately, boards is my major weakness in pinball repair skills. Any ideas on how someone with lame electronics skills can narrow down if problem in on display board versus cpu board? Also, I am working on getting my hands on some known working boards as my lame ass way to try to narrow it.

TY

Ok tried that and when I plug power back into the board, the text displaying the display rom version appears again for a few seconds then dmd goes blank again.

Thanks everyone for the ideas. I did find this post which would add up as the issue. Not sure I want to mess with soldering chips so I think I need to accept shipping boards for repair in my future. I'll post the solution when I figure it out.

https://pinside.com/pinball/forum/topic/stern-whitestar-rct-dmd-blanking-out-help

Here’s the solution. The problem was a bad U201 on the CPU/Sound Board which is the interface for the plasma controller. So it really was the exact same problem as that old post I linked. This info comes from Chris Hibler who repaired the board. So, somehow it got damaged during the install which I am not sure exactly how. Thank you again northvibe and Mattyk for troubleshooting w/me.