Check and see if the opto board is plugged in and working.

If you are running an older CPU ROM then the drop bank bad coil etc error is expected if you go into test mode with the drop targets down. Corrected in the later CPU ROMs which I believe raises the targets when you open the coin door. Easy to figure out by turning the game off/on to bring all of the targets up then run the test with the targets up. That error should go away. I still have an older ROM so I just ignore that error if that particular target is down.

Well ... there's key #1 : you need to order a new set of ribbon cables from Great Plains. Yours are 20 years old!

As for the mini-pf motor, two things to check ...

#1 - are the optos working or not? Easy to test ... remove the mini-pf, and in switch edges test mode, stick a flat blade screwdriver in each one (simulating the pawl of the motor assy), and see if it shows on the dmd. My bet is, they work.

#2 - presuming the optos work, then go look at the motor control PCB under the playfield and see if the large copper coils have cracked where they're soldered to the PCB. Resolder if so.

(note - if optos don't work, check other optos in the game ... it's possible you have a failure in your +12 unregulated power supply, which can also cause this ... but it should cause a bunch of other failures too)

I got mine from Australia.. Homepin

http://www.homepin.com/poa.html

Your scenario sounds so familiar. I just went through this with IJ a few weeks ago and the Homepin board resolved the issue. Nice folks and the part arrived much quicker than I expected.

I’m resurrecting an old thread related to my current issue.

I received the POA “error mini bad pf (switch 94/95)”. The Optos on the board behind the POA do not register in switch test when I run a zip tie through them. I gather they should?
I read all the threads and replaced the opto board first and when that didn’t work I replaced the motor driver board and no difference. The lights on the original motor driver and the new one both illuminate.
During test the POA moves up a little (right) then back to neutral and will not turn left. Same behavior from the motor/arm when I removed the POA.
Has anyone run into this situation? Is it time to replace the motor? Does anyone have access to a new motor? There’s a two month wait at Marco.
Photos are of the original before I replaced them.
Thank you.

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I haven’t relived all the content from this 9 year old thread, but stuttering or slow moving PoA can often be the optos on your flipper boards too!