Replacing Sega "Jumbo" DMD

[Steevsee]

Strange.

Do me a favour, and check the capacitors with your meter set to volts DC.

Clip the black probe to the ground wire again and use the red probe to test the positive connector on each capacitor, with the game on.

[delarge]

Machine is on and checked the voltage on the purple wire for both of the big blue capacitors. Range went up around 0.09 and would drop to about 0.03 on both of them.

Have included a picture of my multimeter to show that it is on DC.

Cheers!
Adam.

[Homepin]

In situations like this meter readings of 0.0XXX can be ignored, they are not real readings.

You are looking for an indication of volts present and they should be "worth" reading - things lke 5.0V, 12.0V etc.

Ignore anything after the decimal place it will only confuse things and isn't relevant.

I would class a reading of 0.0XXX as no voltage present.

Seems you have a broken wire/connector/trace/fuse or an open circuit bridge rectifier that isn't passing the voltage through?

This is a very simple circuit - if you have AC volts on the bridge rectifier and no DC volts coming out then there is a major short on the DC side or the bridge is incorrectly wired or open circuit. There really isn't much else to be wrong.

[delarge]

I haven't tested it yet, but could the BR on the main power supply board be bad for this to happen?

[Steevsee]

Machine is on and checked the voltage on the purple wire for both of the big blue capacitors. Range went up around 0.09 and would drop to about 0.03 on both of them.

Have included a picture of my multimeter to show that it is on DC.

Cheers!
Adam.

Something wrong with the meter or your technique. 
You should definitely be able to measure 18v on at least one of those caps.

[Steevsee]

I haven't tested it yet, but could the BR on the main power supply board be bad for this to happen?

Short answer - No.

[delarge]

Got another multimeter out of the cupboard and still getting 0.0X readings off the DC wires coming out of the bridge rectifiers. As a test, I did the same thing on the other two BRs below BR3 and they read the same....

[beaky]

when you have your voltage problem sorted you will need to change the jumper on the display to suit the pin the 12v is supplied on (1 or 4)
i just had a look over some schematics and:

the original BABCOCK display uses pin 1 for the +12v display
BUT the DALE display uses pin 4 for +12 to +24 volt and pin 1 for the +5v

this is in listed in the schematics section in the batman forever manual.

[Steevsee]

Machine is on and checked the voltage on the purple wire for both of the big blue capacitors. Range went up around 0.09 and would drop to about 0.03 on both of them.

Have included a picture of my multimeter to show that it is on DC.

Cheers!
Adam.

Something wrong with the meter or your technique. 
You should definitely be able to measure 18v on at least one of those caps.

Sorry Adam, didn't mean to sound short here, just typing from phone.

Could you try testing the capacitors again, this time place your black probe on the negative terminal and red on the positive.

Unless you have blown several fuses you should be able to get a decent volt reading on at least one of the capacitors.

[delarge]

On my phone also at the moment. Didn't think you were short, although it's understandable if people are. Appreciate everyone's perseverance.

Ok, this is now getting proper readings.

They both measure around the 19V mark.

[GORGAR 1]

..

[delarge]

I've been mowing the lawn this morning. I think it's taken me 3 hours when it should have taken me half that time. I kept checking my phone and running in and out to test the pinball machine. I'm not going to let this thing beat me! I feel it's so close.

Very thankful of everyone's input. I am learning by some small mistakes, but getting there in the end. The multimeter tutorials are great also.

Thanks again,
Adam.

[delarge]

..

LOL?

I read your comment before Pete and now it's missing. We've now entered the Twilight Zone....

Furthermore, I hope this thread helps someone in the future with these large DMDs. I'm going to take a photo of the instruction sheet that come with the board and the jumper later tonight and put it up here as well. This is a brand new Vishay bran DMD and not like throwing it in like a normal DMD. Of course, I've had other issues as well. hehe

Ok, back on track.

[GORGAR 1]

Glad you got my joke Adam and knew you would as we know each other but didn't know if it would go down well with other members that didn't know that lol

Peter

[Steevsee]

On my phone also at the moment. Didn't think you were short, although it's understandable if people are. Appreciate everyone's perseverance.

Ok, this is now getting proper readings.

They both measure around the 19V mark.

Excellent!

Now is the time to sort the pin issue.  Hopefully, you can now get a good volts reading at the '12 volt' pin on the display connector.(blue wire)

I'd still be inclined to stick with the instructions that came with the display as far as pin 1 vs pin 4.

Once you test the blue wire, reconnect the display and cross your fingers.

Hopefully that brand new display will spring to life.