Fresno, CA
My magnet on the Dr. Dude playfield stopped working. All the fuses are good. Where should I check to get this working again? Any help is appreciated.
(Topic ID: 145966)
Linked Games
Dr. Dude
Bally, 1990
Topic Gallery
Did you pull the fuses and check with a meter? Is there DC voltage present at the connector to the magnet?
Marc
Piershil
Maybe looking at the Tech Chart can give you an idea.
http://www.pinballrebel.com/pinball/cards/Tech_Charts/Bally_Dr_Dude_Tech_Chart.pdf
It looks like the wire is routed through the interconnect board.
Check all pins on the interconnect for bad solder joints.
It might not be a bad idea to do that on the other boards too.
It was the driver board under the playfield. I reflowed the solder and with all good now. Now I just have to figure out why the Big Shot guy is not working....I think its more of the same. Thanks for all the help.
Ok so here's a new problem. The jump bumpers were working fine. Now 2 of the 3 are working. The one bumper will make its sound effect when hit but the coil is not working. Any thoughts? Thanks
Wellesley, ON
Quoted from bicyclenut:Ok so here's a new problem. The jump bumpers were working fine. Now 2 of the 3 are working. The one bumper will make its sound effect when hit but the coil is not working. Any thoughts? Thanks
Either a burnt coil or a transitor or both.First check the pop bumper coil to see if it is burnt up. If its ok find the transistor for that pop bumper and ground the tab on it see if the pop bumper fires.
Quoted from Inkochnito:It looks like the wire is routed through the interconnect board.
This is a good place to start.
So I'm really confused and frustrated. Here is more details on my 2 problems with my game.
1) only one of the pop bumpers is NOT working. It scores and makes its sound effects but doesn't move. The other 2 pop bumpers work fine.
2) Big Shot does not move. Sound effects work and scores but the coil is not engaging.
Here is what I have replaces:
1-Interconnect board
1-Aux board
Both boards are new and from Marco. The pop bumper (all 3) were working fine before I replaced the interconnect board and it worked after. The one pop bumper just recently stopped working. On the interconnect board the little red light is now on that says "A/C Relay C when lit" But I cant find where A/C rely C is? Can someone point me in the right direction?
Thank You.IMG_6540.jpg
Auckland
First thought - according to the manual, neither of those coils you mention are related to the A/C relay. The pop bumper is special-driven, and the Big Shot coils are regular (non-multiplexed) solenoids. I'd
1. Try firing the solenoids manually, by grounding the switched side lug on the coil itself. If that doesn't work, either the solenoid is faulty, or it's not getting power. Stop testing now, and figure out why there's no power to that coil (would be weird, if the other coils are all OK).
2. Try grounding the corresponding driver transistor body on the MPU board. If that works, there's an MPU problem. If it doesn't, there's a problem in the loom or interconnect board.
The solenoid table in the manual is your friend here. It tells you everything you need to know, including which pins on which connectors each coil uses.
The A/C relay is on the aux power supply. On those coils check for voltage at both lugs. If you have power, then ground transistor tab for each coil. If the coils fire then, your problem is on the MPU board. Let us know what you find.
Coils don't go bad very often. Check for power on the red/white wire first. If good you check to other terminal on the coil. If you have power there then the coil is good. Then look in the coil chart for this coil and it will tell you which transistor on the MPU board controls this coil. Use your jumper from ground braid in the back box to the tab on the transistor for this coil momentary. If the coil fires you have a board problem, if it doesn't fire then its the wire from the board to the coil. Also you can't use the metal parts on the playfield as a ground connection for testing because there aren't grounded.
Just for clarity's sake - don't do anything with the power. Trying to connect it to another coil at this point is just going to confuse things. Just earth the switched side. As Grumpy says, don't earth it to any of the playfield brackets. Annoyingly, there are very few (if any) good ground points on a playfield. Probably the easiest place to ground it is on the earth braid in the cabinet (usually stapled to the sides or bottom).
Check. Ill go do it again. I understand what both of you are talking about. Thanks, Ill report back.
But you still don't know if there is power at the red/white wire. Do you have a meter to check for voltage?
I see that power cable to the other coil's still there. Not ideal, but at least it should guarantee that the coil you're testing has power. To be sure, try doing the same thing to one of the working coils. That *must* fire correctly.
Grumpy's suggestion of checking voltage with a meter at the coil is a good one, too.
Ok guys, I screwed up. So here's what I did. I went ahead and ordered and new pop bumper coil, thinking that they aren't that expensive so might as well. I honestly didn't think that was the problem but i got one anyways. I put it in tonight and sure enough it didn't do anything. So I did some more testing. I took the power lead to this pop bumper that isn't working and replaced the power lead on a pop bumper that was working....sure enough it worked. So to me its not the power side. That is clearly working. So I went back to what you guys were originally saying for me to do and make the pop bumper fire. I put the power back on the pop bumper coil and grounded out the other side but forgot to disconnect the other wire. Now what it does is pop 2.5a fuse on the Aux board. Also I noticed Q73 (Transistor) on the CPU board was smoking. So I guess I need to replace those now. Im assuming that's why I kept blowing the fuses, because I fried the Q73 transistor?
Anyways....I have to go find some locally or order some. Ill keep you posted.
Update.... I bought a new MPU board. It's a rotten dog board. I moved the CPU chips over and popped it in and all the pop bumpers were working as it should until about 5 mins later I lost the bottom pop bumper again. Big shot still doesn't work. I've replaced all the boards except the sound board and the power supply board (top right corner). Not sure what else to try. I've put all new fuses and checked the ones on the playfield. I'm stumped
Replacing the boards isn't the best solution. Problems on the playfield and other boards can cause damage to the new boards, that's why you should never swap boards to test. I asked before, do you have a meter? A good meter is the best way you can spend your money. When a coil doesn't work you check for power on both coil lugs. This tells you two things, there's power and if the coil windings are good. If these both check out you can check the rest of the wiring by grounding the transistor tab briefly, if the coil fires the wiring is good. This also tells you that the problem is on the MPU board. Remember anytime you replace a burnt coil or a shorted transistor you must replace the corresponding pre driver and diode or you will burn up the new parts you just installed. Pick one of the problem coils and fix it before going to the next.
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