Phonoland

I think my is exhibiting the dredded Rockola magazine/gripper motor death slide. It turns like normal for a bit then all of a sudden the motor bogs down as if it were stressed and then blows the fuse. I removed the motor and the magazine turns freely. I tried the motor unattached and it exhibited the same behavior as above and burnt out the fuse. I looked up how to test these motors here:
http://www.groschopp.com/how-to-check-a-motor-armature/

These were my results:
1. 180 deg commutator test:
5.9, 7.2, 5.4, 5.8, 2.8, 2.2 ohms

2. Commutator Bar to bar:
Rage from 2.4 and 3.0 ohms

3. Commutator bars to armature:
No conductivity

I know that number 3 is a good test but I don't know if the range is too large on tests 1 and 2. The directions say that they should be close, but I don't know how close? I hope someone on here with a little more knowledge can help.

Thanks,
Josh

A few pictures:



I don't think the commutator looks too bad and the brushes have 15mm of material left.

Hi Josh,
I don't know much about motors--but if it blows the (correct size-type ?) fuse when dis-connected, from the gear train, it IS bad !
Those motors can be re-built, at most "small motor shops", or there is a guy who places an ad in Always Jukin Magazine, offering that service.
Ron Rich

Thanks Ron, There is a shop here in Peoria that will probably do this motor work. I was just wanting to pinpoint what is wrong with it if I could. I want to confirm it is the motor and not something upstream causing this. I'm guessing the inconsistancies on 2 of those tests points to an armature failure.

I'm happy to report that after receiving a NOS armature from eBay today, I've got the 444 running smooth again. The motor is spinning super strong now after the rebuild. Now that it's running right, it's easy to tell the motor was really having trouble before. Thanks for all the help!