Lenexa, KS
These are my voltages, 67v,0v,5v,ground,0,-86v, and -110v. It looks like I'm missing 12v. Please lead me to my next step. Thanks!
(Topic ID: 120291)
Linked Games
RollerCoaster Tycoon
Stern, 2002
Topic Gallery
Some Stern display power supplies don't have a 12 volt output, and new displays don't need them. Usually (but not always) a missing 12 volts will generate a kind of smeared line across the DMD. What brand of display do you have? Have you double-checked the power connection to your display board? What exactly do you mean it "dies"? Does it just go off, or fade out?
This is a stern rollercoaster tycoon made in 2002. It has vishay DMD. Power relay board 520-5055-00. Stern DMD driver board 520-5055-00. When I turn on the machine the game boots, the DMD boots correctly and it shows the intro screen which is perfect. No lines out etc. After about five seconds the entire screen goes blank. It never comes back on. I checked all the transistors on the relay board that provides power to the dmd and none gave any weird values. Thank you for the help!
That's your game CPU not booting. Check the power supply to CPU connector, reseat eprom, is led 201 on the driver board flashing? This is not a dmd problem.
1 month later
Back to this problem again. I had a few other repairs. LED 201 is not flashing. I have not reseated the eprom yet. Now I get nothing from the screen, not even the few seconds it worked before. At the DMD controller board I have no 12volt supply. My pin 1 and 2 are also 114/84. Ive been trying to get the 12volt back. I tried the step by step instructions in pinwiki and replaced the 74hct273N but that did not help. Thanks kbliznick for your help.
Do you have 5 volts on the DMD controller board when the problem occurs?
If not, then resolder the 2 pin (red/black) male connector on the board.
Likely if this is the issue, you should be able to wiggle this 2 pin connector and see if it causes the display to go blank/reappear.
Its a Vishay display. Yes I have 5 volts on the controller board. I resoldered the 2 pin today, it wasn't loose but I figured why not. When I first tried this, I had perfect data for 5 seconds on the screen, then it would disappear, now I have nothing, followed by nothing. 
Try pushing on thr display ROM on the DMD controller board when it acts up.
Do you have good voltages to the DMD power connector?
Down the rabbit hole.
You never needed the 12V for the displays and there initially was NO problem with your DMD, it was the CPU not booting. Now somehow the display or display driver board has been damaged so now you have 2 problems.
I would call in a tech to figure it out at this point. Best bet would be to test the DMD driver or the DMD in another game to see what else is now broken. Once you get the DMD booting to the test screen again, then you can try to figure out why the CPU wasn't booting.
The -84volts should be about -102volts (12 volts lower than the -114v).
Looks like you need to repair your power supply voltage.
I had the ribbon connector backwards on the DMD controller board. You were correct kbliznick that I created a new problem. I swapped out a new CPU board and fixed that ribbon cable and it now works. It looks like the chip on the U201 on the CPU board needs to be replaced. Every now and then I just have to sit back and look at all of the tests I've ran, what I have swapped and deduce where my problem lies. Thanks for all of the help! 
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