Hi everyone ,I am restoring my GNR and everything worked just fine until I got it all back together and now just the DMD will not come on at all but everything els works fine as it should anyone know what could be why the DMD is not coming on ,is there a fuse for it too check ?
Thanks, for any help on this
Quoted from Williampinball:Ok will try that first and let you know thanks
Sounds good
Check the orientation of the ribbon cables, shown in yellow boxes. If one is swapped around on one end, that will give a blank DMD.
Also make sure you have 5volts to the power connector to the DMD controller board, shown in the orange box. Sometimes wiggling this connector can bring back the screen.
If any of that does not help, test the voltages (-112v, -100, 12v, 5v, 62v) at the DMD power connector.
Quoted from PinballManiac40:2 fuses? I believe you might be thinking of B/W DMD controller board.
Oops sorry yes I was thinking of B/W..
so far the ribbon cable is right the Red line is both on #1 I will check the others later today and get back you all thanks for the help .
Quoted from PinballManiac40:Probably a good time to test the (-112, -100, 12, 5 and 62) voltages on the DMD power cable.
Ok how do I check them ,I just check the 5v and its ok there's 5v there
DMD power connector is on the left side in the red box. You can use pins 4 or 5 for your ground meter lead. Remember not to cross the streams (meter leads). Sorry for the GB joke.
1 -112v
2 -100v
6 12v
7 5v
8 62v
2019-12-10 13_58_56-DMD not working on GNR _ Data East _ Sega _ Pinside.com - Internet Explorer (resized).pngDMD voltages (resized).png
Ok lol I am getting
1-114.9
2-92.2
6-5.0
7-12.0
8-.3
So 6 7 8 not good 8should have 62v and it doesn't ?
Quoted from Williampinball:Ok lol I am getting
1-114.9
2-92.2
6-5.0
7-12.0
8-.3
So 6 7 8 not good 8should have 62v and it doesn't ?
Would u know why 6,7 is the other way around 8 has none thanks for any help
Quoted from Williampinball:Would u know why 6,7 is the other way around 8 has none thanks for any help
Right, other way around. I was trying to remember off the top of my head.
So having no 62v is not good. Post a picture of your power supply please.
1 and 2 should only have 12v difference, so currently that is even a problem if the DMD is still connected. Power supply rebuild sounds in order. Also, the capacitors are old as well, so would be good to change them too.
What's B/W mean ,and why is there no power too the 8 ,u said it should be 62 v
Thanks again for the help
My GnR dmd was dead when I picked it up. I swapped in my Tommy display and left the controller board and it worked perfectly. There is definitely some circuitry and chips on the actual display and one of the chips was probably causing it to be dead but never did go back and debug it. I could see it got really warm at some point.
This is quite the intense repair. So either have to decide to repair, send it out for repair or buy a replacement power supply. I would recommend the Xpin or another rebuilt original if you go route of another board.
You could also go with a ColorDMD. Then you would not need to repair this section at all since it will not need these voltages.
I don't see any black or dark marks on the power borad at all ,the weard thing is this worked fine before I took it apart and I put it all back the way it was lol
That is the way it goes with the old DE power supplies. One day it can work fine and not another.
The fuse related to the high voltage is the 1/2 amp. If it was out, you also would not have any of the 3 high voltages, -112, -100 along with no 62v.
Need to check also if your DMD shorted out as well. Unplug that DMD power connector. With power off on the game, set your multimeter to ohms and check from the ground pin 4 or 5 to pin 8. If it is zero ohms on the DMD, it will also have an issue.
Quoted from PinballManiac40:Need to check also if your DMD shorted out as well. Unplug that DMD power connector. With power off on the game, set your multimeter to ohms and check from the ground pin 4 or 5 to pin 8. If it is zero ohms on the DMD, it will also have an issue.
Ok thanks so much for your help
Will
Quoted from PinballManiac40:Need to check also if your DMD shorted out as well. Unplug that DMD power connector. With power off on the game, set your multimeter to ohms and check from the ground pin 4 or 5 to pin 8. If it is zero ohms on the DMD, it will also have an issue.
Ok checked the ohms on the DMD seems all good thanks again bud
Happy flipping
If you test the voltage at the end of the DMD power cable without the DMD plugged in and still have no 62v, yep bad power supply.
Quoted from PinballManiac40:If you test the voltage at the end of the DMD power cable without the DMD plugged in and still have no 62v, yep bad power supply.
Grap lol I have a guy coming this Thursday too fix the power board
Thanks again bud
I would be surprised if he has the parts on hand. Not often this failure occurs. I even suggest the power supply gets all new capacitors, as they do wear out. Between the high voltage and capacitors , you may be getting close to a cost of new Xpin board.
Yea this guy has most things on hand but he will want too go though everything first too make sure but I will let you know what it was for sure .
Take care bud
That is great. Still suggest at the smaller sized capacitors get replaced as they do like to leak.
C2 (100uf 25v), C3 (47uf 63V), and C7 (330uf 25V). These caps tend to leak their corrosive contents on the PCB and kill the 5VDC circuit.
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