Replacing Sega "Jumbo" DMD

[Steevsee]

Please don't keep me in suspense for too long!

[Retropin]

Please don't keep me in suspense for too long!

Went back to mowing the grass...

[Steevsee]

 

A man's gotta do, what a man's gotta do!

 

[delarge]

Date night with the lady, heading out to the movies. hehe.

I've attached pics of everything relating to the new DMD. The instruction sheet that come with it, the serial numbers to show which DMD on the instruction sheet it relates to (top left, put an asterisk on it), the pic of the jumper on the board and also the DMD controller board as I thought I might have got the ribbons around the wrong way. Plugged the connector in, turned the machine on, but still no flash of light or any life in the DMD.

Cheers!
Adam.

[delarge]

Maximum of 4 pictures in the last post. Here's the final pic.

Also, you can see I moved the +12v pin back to pin 1 to match the jumper on the board.

[Steevsee]

Just to put my mind at ease, did you measure 18volts at the blue wire?

[delarge]

The blue wire is still DC? I was originally having trouble measuring that wire. Had the red lead on the blue wire and the black lead on the ground braid, but it was only measuring 0.0XX etc.

[beaky]

Your jumper is set right
What you want to do is first set your multimeter to AC and check you have around 12 to 14v AC on the AC terminals on the bridge.
If you don't check the fuse if you do then switch to DC on your meter and check for your DC voltage on the out put of the bridge and on the cap if you do have the Dc voltage then check at the display connector.
If you don't have the correct voltage here then connect the + lead to  to the blue wire on the dmd plug and the - to the - on the bridge. If you do hAve the correct voltage displaying on the meter then this will indicate you have a problem with the ground wire.
If you don't then connect the red meter wire to the + on the bridge and the blk meter wire to the black wire at the dmd display.
If you have the correct voltage on your meter then the problem is with the power on the blue wire to the display.
Hope that makes scene ?

[beaky]

sorry i reposted this but i noticed some things that had to be changed and the time i got to my computer after typing all of that on my phone i could no longer edit it!

your jumper is set right
What you want to do is first set your multimeter to AC and check you have around 12 to 14v AC on the AC terminals on the bridge.
If you don't check the fuse if you do then switch to DC on your meter and check for your DC voltage on the out put of the bridge and on the cap if you do have the Dc voltage then check at the display connector.

If you don't have the correct voltage at the display then connect the + lead to  to the blue wire on the display plug and the - to the - on the bridge. If you do hAve the correct voltage displaying on the meter now then this will indicate you have a problem with the ground wire.

If you don't have the correct voltage then connect the red meter wire to the + on the bridge and the black meter wire to the black wire at the dmd display.
If you have the correct voltage on your meter now then the problem is with the power on the blue wire to the display.
Hope that makes scene ?

[Steevsee]

Hi beaky.
Phones suck for posting!
Adam has already verified 18 volts+ at both caps.

Adam
Was going to  post some pics but try this.
Meter on volts DC.
Black probe on black/red wire of display connector,
Red probe on red (5 volt) wire.

next do the same with the other pair of wires,
Black to black wire And red to blue (18 volt) wire.

As usual let us know result.

[beaky]

is that a 5 volt wire at pin 2?
remember pin 2 and 3 connect together as a ground so if the 5 volt is red black on pin 2 then +5 is shorting with the ground when the connector is plugged into the display
i can see on the paper work that pin 2 and 3 are ground and i can see a trace from pin 2 to 3 on the display in the picture.

if the red and black is +5 volt then you will need to move it one pin to the right so it is in the far right position

[delarge]

Interesting results....

I put the black probe in pin 3 (red/black wire) and the red probe in pin 1 (blue wire). I got a 0.0X reading. With the black probe still in red/black, I put the red probe in the 5V red wire that has been disconnected. I measured the 5V as always.

Now, I moved the black probe to pin 2 (black) and measured the voltage on pin 1 (blue) and my multimeter measured around 19V. What the???

[Retropin]

Ok... kind of following this but i dont have a display so im just reading whats posted.

So you move black probe and you get a reading?.. the red/black wire on pin 3 is not connected or is at 19v ... theres no voltage potential here, so its either the same voltage or youve lost ground here.

Your meter will only read the difference between 2 voltages, so if you have ground ( 0V) and a volatge of 5V it will read 5V on the meter. If you have 5V and 2V on the other lead it will read 3V.

Sounds to me that rfed/black wire also has 19V across it.. or the same voltage as blue

[delarge]

Also, with black probe in pin 2 (black wire), I measured the red 5v wire that is dangling in cabinet now. It measured 0.0X.

[beaky]

am i reading this right?
what i see is pin 1 being far right with no wire and the "number 1" printed on the pcb to the top right.
pin 2 with the black and red wire
pin 3 with plane black
pin 4 with the blue on the far left


what you have there is to supplies without the grounds connected to each other
red and red/black if from the +5 on the power supply
blue and black are from the separate  bridge rectifier for the display +12