Lotr dmd out advice needed!

[J.C.Rox]

Hi guys, @cooldan has lent me his lotr and it arrived today, everything worked, I left it running and came back and the dmd is blank. I've tried repeating every connection and checked the fuse in the display power board and beyond that I'm at a loss. The small top board on the back of the dmd has the led lit so is getting power. How can I check to see what's at fault, I have a Tommy with what looks like a similar dmd with a game specific rom on the back can I swap roms and test the dmds in each other to help narrow down the issue?

Any help gratefully received!

 

[stoptap]

It's going to be difficult to diagnose it without having another DMD to try.
You could start by checking the voltages going to the DMD.

 

[J.C.Rox]

I have other dmds in Tommy but don't have and can't work a voltmeter so bit stuck. Tommy looks like the same layout, small board with game specific rom feeding to dmd underneath but I'll probably blow up one or both of them so I'm pretty stuck really!

 

[Paul R Owen]

My Baywatch dmd is blank and has been diagnosed as a faulty bridge rectifier in the backbox. You need a multimeter and someone who can use it.

 

[J.C.Rox]

Yeah I'm thinking this is above my skill level! Will get out the old yellow pages....

 

[Paul R Owen]

I think Robin Kemp is near you. Someone on here may know?

 

[cooldan]

Doubt it, Robin is on the South coast these days and Jon is in Scotland.

 

[J.C.Rox]

Oh yeah I need to change my location!

 

[stoptap]

At a push you could post the DMD to somebody so that they can try it in another game for you.

 

[Sgt GrizZ]

Can't you just try the LOTR DMD in Tommy .........just the DMD, not the boards from LOTR.....to confirm whether its dead.

 

[J.C.Rox]

Can't you just try the LOTR DMD in Tommy .........just the DMD, not the boards from LOTR.....to confirm whether its dead.

I blew the f7 0 .5a fuse in Tommy when I plugged the whole dmd including the board attached to it. Then took it over to wwf and plugged just the power and feed from the wwf board straight to dmd and blew the same fuse there. Don't have spare fuses so game ends there but I'm pretty certain dmd is shot.

Question. Are the 2 boards below doing the same thing just different eras?

 

[J.C.Rox]

 

[J.C.Rox]

They take the same 5v feed, have a game specific rom, same ribbon cable in and same out to dmd.

 

[J.C.Rox]

What's also strange is the fuse on the lotr dmd driver board hasn't blown?

 

[J.C.Rox]

I tried putting lotr rom in Tommy dmd and hooking it up but no joy....

 

[Paul R Owen]

My faulty bridge-rectifier on Baywatch is blowing the associated fuse.