Make sure the rods are nice a clean, they can easily get some gunk on them that prevent a good left or right motion.

Might be the flipper opto. You can test by switching the boards to see if the stutter goes the other direction.

I had the same issue. Make sure you clean the rod and the slider sleeve with rubbing alcohol.
No lubricant. It should work just fine after doing that.

The previous owner had put lube in the sleeve and it was binding in one direction during play.

Seems to be the same from the video.

Screenshot_20170330-230819 (resized).png

Screenshot_20170330-230403 (resized).png

If you ruled out all the above it could be something weird like the flipper opto board as mentioned above. However every case I've seen has been mechanical though. With the game off can you move the kicker back and forth with out hang up? After the opto I'd look at the motor wires and make sure they're not frayed or pinched, trace them all the way back. Do this and report back.

Check J-126 pin 3 for a cracked solder joint on the power driver board. Replace connector J-126 and header pins if they look bad. If this doesn't help then test Q-38 on the PDB.

You could have swapped them from left to right...I think they're the same part. Check it out and let us know.

If that doesn't work then go with grumpy's advice. What he's suggesting is a high-resistance connection, which would reduce the current to the motor and cause the problem you're seeing.

clean opto 'mini-PF limit right'
MiniPF opto Rgt.jpg

I have the same issue with my game. Works flawlessly in test mode. During game it hangs up like that. Do you clean the optos under the board with alcohol?

Yes.

I can't help you with the flipper issue, but as far as the upper playfield, I had a very similar problem.
It turned out to be a broken wire, under the rubber, at the solder joint. the pieces were just touching, but couldn't carry full currant The wires do flex quite a bit. I replaced my wires with silicone coated that are a bit more durable.
Good luck.

In switch test menu T1, are the flipperbutton-optos responding as they should or are they activated without pushing the buttons ?
(F2,F4,F6,F8)

Mine was caused by a dirty opto on the mini playfield, cleaned it and it works fine.

So this was caused by a bad opto switch?
I'm having the same issue where it goes right fine but chatters when going left.
I just replaced the left opto (5490-12451-00) on the A-14534 because it was bad.

In the mini playfield test the optos both work fine and the game registers when the kicker moves all the way to the left or right.
When you short the motor board inputs to ground the motor moves in both direction just fine so I know it's not a mechanical issue.

when I put my logic probe on the outputs of U3 on the PDB, I see a solid low signal when the right direction (Q38?) is activated. But when you activate the left side (Q36) it pluses just like the motor does.
so somehow the game isn't activating the left side drive fully.

could it somehow think it still has a bad left opto?

Still trying to fix this problem on our game.
I've noticed that while in switch testing that if you fire the flippers or the slingshots that the switch 37 (the left opto) will get activated at the same time.
It will also be activated by the mini playfield test when you use the left or right buttons to go back and forth.
the switch works fine when it should be open or closed but the false closings really confuse the game.
so the problem does seem to be the opto itself.
I replaced it with a OPB804 a few weeks ago because the old one was dead, and thinking back it did start doing this behavior after I did that.
do I need to replace it again with a QVE11233.0086?

FIXED!
I replaced the opto again and this time it works.
Those OPB804 opto switches must be really touchy, some work and some don't.

Sorry to re exhume this old post but I'm having the same exact problem..my kicker moves to the right then all the way to the left and it stops on its way to come back..I've tested the limit switches in the switch test and they register properly. How did you were sure that they were the problem? I attach my error message during test..1 time on 5 it says it's ok!

20180420_001125 (resized).jpg

Bump!

Not sure if it helps any, but I had a finicky battlefield as well. The problem was twofold:

1) the rods underneath were very slightly dirty. Also, a screw holding the left side in was loose.

2) the controller board under the playfield was faulty. I replaced it, and the mechanism now works like butter.

See if the gear strip on the front of the mini pf is in tact. Sometimes the tooth on the ends breaks and stops the kicker from going back.

http://www.marcospecialties.com/pinball-parts/03-9231

Thanks for your replies:

I will double check the screws since surely the rods are well cleaned.

Can you suggest which board underneath the playfield controls the miniplayfield? You mean the 24-opto board?

About the rack , i have not replaced it so it is in used conditions..it's possible that even a little worn can cause this problem?

No, check the DC Motor Control Board (A-16120).

Also, it may help to clean up the rack and pinion of the mechanism. Someone before you could’ve gunked it up with grease.

Another screwy miniplayfield here. During gameplay just like OPs video. I cleaned the optos for left and right limit and that seemed to hep slightly. However the mini playfield test is odd and inconsistent. It seems to work if I manually slide the paddle to the right before turn on the game. Otherwise it will either move all the way left and then stutter right a sec then stop with the message saying the mini playfield works. Tryin again will give me a playfield bad message. The worst is it never stops slightly moving and I have to power cycle the pin. See below.

2 more things: switch edge tests do show the right/left opto switches to be working.

Was going to try and switch the optos to see if that reversed the symptoms but the switches are soldered in so not an easy switch.

24586F5A-1F5F-4DD5-8238-358B422614C8 (resized).jpeg