Checkpoint DMD matrix display troubleshooting

[bfrosty]

Okay,
Trying to figure out why my DMD won't even light up.

So far....
Replaced transistor R95 (suggested among others on the boards)  It did look a little fried.
Replaced capacitor C27 (looked a little fried or dirty)
Reflowed headers on Power supply connection
Add solder to some transistors that look like no solder was on one end. (strange)
Checked w/Multimeter the power cable.  All readings looked okay.

Now, I was going thru the manual and there is a .5A fuse for the display at F3.  Well, look at this pic!!!  The fuse holder is gone.  WTF?

Anyone know why its missing?

[bfrosty]

Update:

In the manual, it only shows 4 fuses in that location.  So F7 must be the F3 Fuse?  It checked out okay.

Here are my readings and what the power connector should be pushing out.

My reading    |  Factory Spec
-108vDC             -100vDC      < Is that bad?  8v more than required?
-96vDC               -98vDC        < Is that bad? 2v less than required?
+68vDC              +68vDC       < Good!
+12vDC              +12vDC        <Good!
+5vDC                +5vDC          <Good!

All others are grounds or key.

Okay,
Trying to figure out why my DMD won't even light up.

So far....
Replaced transistor R95 (suggested among others on the boards)  It did look a little fried.
Replaced capacitor C27 (looked a little fried or dirty)
Reflowed headers on Power supply connection
Add solder to some transistors that look like no solder was on one end. (strange)
Checked w/Multimeter the power cable.  All readings looked okay.

Now, I was going thru the manual and there is a .5A fuse for the display at F3.  Well, look at this pic!!!  The fuse holder is gone.  WTF?

Anyone know why its missing?

[iankellogg]

Those voltages look fine. the 100V is going to be for the DMD display so I would start looking to see if the DMD display is getting that 100V. I would also make sure the ribbon cable is connected and okay. Its possible the DMD controller chip is just dead.

[bfrosty]

Ian -

Is the DMD controller chip located on the DMD board?  What does it look like?  Can it be replaced?

Thanks,
MK

[iankellogg]

yes it is on the dmd board, it is a surface mount chip so you will probably not be able to replace it yourself. It is not commonly available and probably not worth your time. I would start looking at buying a new display.

[bfrosty]

I put an order in with PINLED in Germany...I know...I read all the messages about him.  It was really my last resort.  We'll see if he delivers.

I tried to bid on a display on Ebay...the thing went from $200 and sold for $358.  Ugh!!!!

Its still very fun to play this pinball even though the scoreboard isn't working.  The kids love it, just wait till it keeps their score. 

All broken pieces have been replaced and 95% of the playfield lights are working.  Cleaned it up and looks great.

MK