I just had an interesting experience with my JD.

I was playing it (good thing not a high game going) and suddenly i started noticing that the deadworld was making a slightly differnet noise than usual (it usually makes a typical gearbox sound, sorta like a grind, but the pitch of the sound changed as if it slowed down a little bit).  Also, the 5-bank target was acting really strange, like taking several attempts to re-rack the targets...I kept playing though just paying close attention to what was going on.  Then my game shut off, came back on...i restarted a new game, the plunger wouldn't fire the ball (could just be coincidental, sometimes it doesnt fire right off the bat, whther it's just out of sync with the ball getting ot the plunger or what).  At any rate, i started to smell something burning.  I immediately shut the game off and unplugged it.  Looking around I saw smoke coming from the very back of the playfield.  I touched the coil that controls the diverter and it was extremely hot.

I guess my question is, is this simply the coil burning up, or did something happen on a circuit board somewhere to cause this?  I'm hoping it is just the coil burning up and a simple fix...

I tested the TIP102 transister and it's blown.  It is Q54.  I'm having trouble finding out which pre-driver goes with taht one.  If anyone can tell me the easiest way to figure that out, I'd appreciate it.  I don't have extra schematics with the machine, just whatever is in the manual.  I THINK it is Q53 (Based on T-2 actual wire schematics that i have, Q53 goes with Q54.  I know, differen't game, but the layout is probably the same.  That checked out fine, but i might as well replace it anyways.

I wonder if I shoudl replace the coil since it was smoking it was so hot.  

Quoted from Firehawk734

I wonder if I shoudl replace the coil since it was smoking it was so hot.  

I would at least replace the Sleeve, If it got that hot, you might not even be able to get the old one out.

Quoted from Firehawk734

I wonder if I shoudl replace the coil since it was smoking it was so hot.  

Yeah. That smoke is the insulation on the windings burning. If it didn't burn right off it's probably brittle and may break. Then your into a short.

Grinding sounds are not good. It sounds like it was too much load for something electrical and caused the burn. I would check my motor gearbox on a fused bench supply and see if it needs a new gearbox and now possibly motor. Sounds like your going to pop that transistor again.

Doubtful you circuit board caused the problem. It is more likely that it suffered from whatever is going on with that smoking assembly.

Schematics

Here
http://www.pinball-fixers.com/bally-pinball-schematics.html

and here
http://files.flipperspill.no/Support/Pinball/Pinball_Related.htm


Game manual here

http://www.ipdb.org/files/1322/Bally_1993_Judge_Dredd_Manual.pdf

What your looking for is in the game manual. You should not be required to go into the Schematics to get the right transistors. Doubtful you will need to play with the predriver for the failure you described.

The globe motor transister seems fine.  By grind, maybe I didn't say it right.  It's always made the same sound since I've had the JD.  I figured it's just supposd to make that sound, especially since there is play in the deadworld, maybe gears are in fact worn,and if i were to get the gearbox rebuilt it would be quiet, but i really don't know. I  haven't seen another JD to know if when the deadworld is spinning it is silent or very quiet.  What i meant was the pitch of the sound suddenly changed, as if there was not enough current going to the motor, and pumping into the diverter coil or something? The pitch of the sound generated by the deadworld spinning did change a little, and my 5-bank target assembly started acting goofy...

When I looked into it further, i only found that Q54 TIP102 was bad.  Q66 (globe motor transister) was fine.  Fuse F104 blew also but it took awhile lol.  Just the diverter coil was smoking and extremely hot, nothing else (not the motor or gearbox or anything).

Oh one other thing.  I did notice while i was still playing the game and it was acting weird, that i shot the ball around the big deadworld ramp twice and the diverter did not stop the ball like it should of, didn't even make an attempt.  That tells me the coil was not firing.  Could it have shorted and gotten that hot, causing the TIP102 transister to blow?

Quoted from Firehawk734

Oh one other thing.  I did notice while i was still playing the game and it was acting weird, that i shot the ball around the big deadworld ramp twice and the diverter did not stop the ball like it should of, didn't even make an attempt.  That tells me the coil was not firing.  Could it have shorted and gotten that hot, causing the TIP102 transister to blow?

If it isn't your motor seizing up but instead that diverter coil you may have had the transistor blow and get stuck on. That could keep that coil energized until it smoked. The coil should measure at least above 3 ohms resistance depending on what it is. I would check that it isn't shorted at this point.

If the transistor stuck on what you may have had happen is the coil burned, shorted then blew the stuck on transistor or just the fuse. I would check to see if that transistor is stuck on right now, that would give you a good indication of this happening.

The other issues may have been as a result of the load this put on the regulator circuits.

If your Deadworld sounds like two skeletons f@#*ing on a tin roof, it's time to get a new one. They usually run about $80 but JD was a game that got parted a lot so you might get lucky.

I hadn't been able to find a new gearbox, and when i looked into it someone wanted to charge 300 bucks to rebuild it.  I thought that was ridiculous and would just play it until the thing quit working.  There's probably a good inch side to side of play in the deadworld (i can move it manually that much), so I know it is worn, but it still seems to function correctly.

If i had a brand new gear box (rebuilt or good used one), would it be silent or damn close?  Right now it sounds like a remote control car.  You know the ZZZZZZZZZZZZZZ sound a remote control car makes...that's what it sounds like, always has since i owned it. But as i said, it still works properly lol.  It is quite loud though.  I hvae the pin in a corner of the room and that doesn't help with the noise coming out the back of the machine and deflecting off the walls.  If i could find a gearbox for 80 bucks i'd probably pick it up.  If you know of any please don't hesitate to let me know.  I appreciate it.

Also, i finaggled the coil out of the diverter assembly and the damn thing was toasted.  When i measured the resistance, it was 0 lol.  I couldn't get anything more than 0.06 Ohms (60mOhms) out of it.  Musta really blew up.  At any rate, I'll order a new coil, and I just got done replacing the TIP102 and 2N5401 pre-driver (this wasn't blown, but i replaced it anyways).  

So i got evertyhing hooked back up (except diverter coil, it's ordered) and everythinbg seems to be working just fine now, cept nothing loads into the deadworld due to the diverter not working, unless it happens to fall in there.  So i appreciate any help.

What I'd still love to know though is the degree of noise that is considered 'normal' from the deadworld spinning.  If it would help, I can take a recording and post it up to see what you gurus think about it.  Both the lifter and the deadworld make comparably the same amount of noise when in motion.  But, they still work properly and I have them set right.  So I'd really love to know...

Quoted from Firehawk734

If i could find a gearbox for 80 bucks i'd probably pick it up.  If you know of any please don't hesitate to let me know.  I appreciate it.

Not sure its $80 .. but its worth asking.  Ping Steve @ PBR

http://www.pbresource.com/motor.html

Judge Dredd     14-7985    Planets
(Not Available New -We can offer to have your motor repaired– contact us)

I would also contact this guy, in case not everything went to ebay:

http://groups.google.ca/group/.....tor#b01458c3eb53e346

Quoted from Firehawk734

What I'd still love to know though is the degree of noise that is considered 'normal' from the deadworld spinning.  If it would help, I can take a recording and post it up to see what you gurus think about it.  Both the lifter and the deadworld make comparably the same amount of noise when in motion.  But, they still work properly and I have them set right.  So I'd really love to know...

All those gearboxes from Multi Products are a bit noisy. I haven't had a motor and gear assembly yet that didn't make a fair amount of noise, including my Judge Dredd. Replacement if available is way cheaper than getting those bandits at Multi to "rebuild it". I am almost certain they throw yours in the trash can and sell you a new one for a premium price since the distributor does not carry it.

I would crack the case on it if you can't find a replacement. From what I found in the past, the gears wear at the point of contact but often there is plenty of gear left if you shim and spacer the gear pack to a different gear contact point. I had to do this with PZ until I found a replacement, but I am sure that fix would have lasted forever in home use had I left it in.

Well if the noise is common then I guess I won't fix it until it breaks and then see about rebuilding it or doing what you suggest with shiming and spacing the gears differently.  I thank you all for the advice.

I don't remember where I looked into getting it rebuilt, but they replied by email, "For $299.99 we'll have that gearbox rebuilt as good as new".  I thought that was assinine.

Quoted from Firehawk734

Well if the noise is common then I guess I won't fix it until it breaks and then see about rebuilding it or doing what you suggest with shiming and spacing the gears differently.  I thank you all for the advice.

I don't remember where I looked into getting it rebuilt, but they replied by email, "For $299.99 we'll have that gearbox rebuilt as good as new".  I thought that was assinine.

Well I know a few years ago the manufacturer here would do it, and it was pricey. Last resort I would say. I have found they have similar products and it may just be a different shaft in it. So it's possible to also source the right motor and gear reduction and just swap a shaft. It's the gears and the bearings that go on them. Not the case and shaft.

http://www.multiproducts.com/