Need some help with my coils.

OU Flight

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Trying to get my Elektra up and running, but am having coil issues. The flippers and one coil (channel gate next to shooter) work but nothing else does. When I do the coil test I also hear a click noise from the backbox for one of the coils.

I have checked:
1. All coils have power
2. Continuity between each pin on MPU J4 and Solenoid Driver Board J4
4. When the transistor tabs are grounded on the SDB the coils will fire

Where do I go from here?

Thanks,
Joe
 
I will check that. I do know there are some that are not passing the self test. I was using the self test to check the coils with those results. Will bad switches cause the soleniods to fail the self test and not fire?
 
I was trying to use Pinrepair for my guide "sigh" and I think I remember it saying that it is possible it may be a chip causing problems if everything else checked out. The only version I can find on the internet now doesn't mention this, or I just can't find it again. Does anyone know what I am trying to say, or is my memory just wrong?
 
I was trying to use Pinrepair for my guide "sigh" and I think I remember it saying that it is possible it may be a chip causing problems if everything else checked out. The only version I can find on the internet now doesn't mention this, or I just can't find it again. Does anyone know what I am trying to say, or is my memory just wrong?

The chip you're talking about would be the CD4514 4-to-16 decoder on the regulator/driver board. That chip lets the MPU drive 15 coils with 5 wires (4 signals and an enable).

The decoder could definitely be the problem but the problem could also be with the signals going from the MPU to the regulator/driver board. I notice that you checked continuity of the wires from the MPU to driver board but I would take it a step further and check right from the PIA pins to the decoder pins. Then you could use a logic probe with the game in solenoid test to ensure that the signals are actually toggling (could be a PIA problem as well). If you suspect a PIA problem, swap U10 and U11 on the MPU and see if the problem changes. If all of that stuff checks out then it's time to replace the decoder.

Personally I would probably just bench test the 4-16 decoder using the data sheet and go through the MPU with a test ROM to ensure all of the PIA outputs are working as expected.
 
Thanks Lindsey,
Couple of noob questions...I'm trying to check the continuity from the PIA to the Decoder, but I'm not sure how. Buzzing it out with the DMM doesn't work because it doesn't show continuity through the resistors. Am I doing something wrong? I was testing from the J4 pin to the legs on the PIA.

I swapped chips U11 and U10 with no change.

Is there something that will walk me through bench testing the decoder, because I have no clue on this.

Thanks
 
Ok, I took a break from trying to figure this out. Haven't touched it in a long time, but would like to get it going now.

Any help figuring this out will be greatly appreciated. What should I do first to get this going?

Thanks,
Joe
 
It could be a PIA but I would look for cold/ bad solder on the pins of the MPU. The board rev is really bad ablout cold soldered pins.
 
Still haven't gotten anywhere on this one. This is my first pin and I would really love to play it. Like I said, I am basically lost now. I just got done checking the pins on both the MPU and SDB and reflowed the solder on both.

Would anyone mind walking me through this one or just telling me what is should do with this thing. It's been in my garage for over a year now.

Thanks
Joe
 
Finally got this fixed! I ended up replacing the MPU with an Ultimate MPU because after all the fiddling with the old MPU it quit working on me. This did nothing to solve the coil problem though. I then replaced the decoder chip on the SDB and the rest of the coils work now.

Next up to fix the Squawk and Talk board with a cap kit. The sound has been intermittent and now is not working.

One down!
 
Hey Joe, if you think you can get the game up to the Preserve, I can come by there and get everything working on it, including the squaw & talk. I have several machines that use the S&T and have good solenoid driver boards as well. Did you have your surgery yet?
 
Thanks Erich. I am on my way home from the surgery now. Feeling good.

I'll have to see if I can get it up there. My plan was to at least talk the S&T board up there to do the cap kit that I already have here. Thank you very much for your help. One day we will play this pin!
 
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