Replacing Sega "Jumbo" DMD

[delarge]

Since you have recently replaced BR3,  I'd probably start there.

Yep, looks like it's BR3. Giving me all kinds of crazy readings on the multimeter. There's my job for tonight....

[delarge]

Ok, unplugged the new display. Replaced bridge rectifier 3 and put a new fuse in F3. Turned machine on and there's a BIG flash in the fuse and it blows instantly.

Any ideas, guys?

Cheers!
Adam.

[Homepin]

bridge installed incorrectly?? Obviously a short somewhere.

[studley67]

homepin,i also have a large sega display that had a burn out of tracks on the ascociated board that joins onto the plasma panel.i tried to fix it but i had to remove(peel)some of the flex ribbon to get to the solder side of the board.Not realizing that i could not re-attach the flex ribbon.The display is now stuffed !!.if you need it for the developement of your LED version you are welcome to it.less discount on your new one.lol
ps the panel was not out gassing.i just had a small fire on the other board.

Thanks - happy to have it mainly for accurate size measurements etc. It doesn'tneed to work.

Also happy to pay whatever reasonable pack and postage costs. Anyone who helps will qualify for a discount 

Cheers

display is in the mail,cheers

[Steevsee]

This is the circuit diagram from Baywatch manual to compare BR3.

I assume Batman would be the same.

[Homepin]

Not much to go wrong there. Unplug everything and measure from the +VE side of the bridge to ground - it should read high as in several hundred ohms and probably rising slowly as the large capacitor charges up.

Has to be a bridge either faulty or wrong way around or a solder splash on a track or between pins when reflowing the solder on the connectors???

[delarge]

I had a friend help me last night and assumed he had it covered when he placed the wires on the legs of the BR. I soldered away without checking. Before bed, I compared the new Bridge Rectifier to the one I removed and the wires are all wrong. The positive side of all of this is that I now know more about the workings of a pinball machines and Bridge Rectifiers.

Thanks Steevsee for the diagram also.

[Steevsee]

That's cool Adam.

As Mike said, not much else to go wrong other than BR3.

Glad you have it sorted, or soon will have.

BTW if Mike no longer requires the old display and your friend is wanting to part with it, id be interested.

[Homepin]

Looks like I have one coming from Studley so this one is all yours....

Studley - please send me a PM with postage cost and bank/PayPus details

[delarge]

Well, looks like I'm back where I started from. Kind of.

Put a brand new bridge rectifier in the machine at BR3. Wired it to the manual image. Turned everything on and fuse no longer blows. I tested the display and once again, no life at all in the display. I checked the voltage on the wire that is marked 12V going into the display and there's a slight murmur there. 5V line is strong.

I can't understand why the machine was working fine with the faulty display, but now the new one won't fire up?

Cheers!
Adam.

[Pintoxicated]

Different displays.  The new one doesn't require the 5V at all and relies totally on the 12V.  You have 5V there but no 12V.  If you are 100% sure you have wired up the BR correctly and it still isn't working them it must be something further up the chain.

The one that came out of the machine isn't worthy of going back in the machine, a very large section is out-gassed and very dull.

Re-check that jumper you soldered on the DMD board to make sure there is no solder splatter as Mike suggested.  Have you disconnected that 5V wire from the connector?   Remember that you only need the blue wire connected.

[studley67]

Looks like I have one coming from Studley so this one is all yours....

Studley - please send me a PM with postage cost and bank/PayPus details

mike,glad to help out mate.just remember the discount when a new display is available.

[delarge]

Different displays.  The new one doesn't require the 5V at all and relies totally on the 12V.  You have 5V there but no 12V.  If you are 100% sure you have wired up the BR correctly and it still isn't working them it must be something further up the chain.

The one that came out of the machine isn't worthy of going back in the machine, a very large section is out-gassed and very dull.

Re-check that jumper you soldered on the DMD board to make sure there is no solder splatter as Mike suggested.  Have you disconnected that 5V wire from the connector?   Remember that you only need the blue wire connected.

Heya Blair,
Yes, moved the blue 12V wire to the 12V slot and totally removed the 5v wire and put a bit of tape around the connector. The jumper I solder was a solid line to eac point on the board and used the solder sucker if there was any splatter. It left two clean points on the board.

100% sure the bridge rectifier is wired correctly....the two single blue wires don't need a specific lug? The fuse is still working.

Thanks all for your help!
Adam.

[delarge]

Ok, double checked the new bridge rectifier with the multimeter and its acting like the other two BRs below it and no crazy readings so all good there. Did a quick test of all the other fuses and they're all good as well.

[Steevsee]

Sounds like the bridge is sorted but here is a pic of mine to double, triple check.

Can you test the connector with the blue wires to see what reading you get.
Set meter to volts AC, doesn't matter which probe goes on which side.

What reading do you get?