Pioneer CT-F4242 low torque and stall from motor

[MrCrabs]

Good day All,

I picked up a Pioneer CT-F4242 cassette deck that was not moving anything, play, FF, RW. Broke it down and discovered all the belts disintegrated and the motor hub was spinning in air. After a complete breakdown, removal of the expired black belt goo, then a clean, lube, new belts, and rollers, I am experiencing low torque then stall with fast forward and rewind. Suffice it to say this "new auto stop" feature is not what I'm seeking or what the designers intended.

Looking into the service bulletins, I notice there was a motor change from the RXM-027 to the RXM-038. It appears the 027 did not have sufficient power and they swapped out the motor then by-passed the 2200mF cap. Looking at my unit, lucky me, I have the RXM-027 installed. I have been scouring the net for several months to find an 038 to substitute but no luck. The 038 was used in several units (CT-6, CT-606, CT-F4242, CT-F7272, CT-F800, CT-F850, CT-F900, CT-F950) and I've toyed with the idea of purchasing a "for parts" unit, cannibalize the motor and part out what remains but the F4242 is on the lower end of the scale and investing beyond another F4242 doesn't make sense IMHO.

The deck is in excellent shape otherwise so I hate to play chop shop and sell off as parts. So, I am up for ideas from the community on creatively solving the problem and getting this deck auto stopping as design intended. No such thing as a foolish recommendation for, so chime in at will.

Thanks in advance.

 

[radiokom]

I believe it is not a motor problem, but idler (-s).
This thread may help at least how this deck looks inside (who designed something like this and what he smoked I can not imagine).

Pioneer CT-F4242 - Repair and work in progress thread

A week ago I landed a free to me Pioneer CT-F4242 that “didn’t work” or so I was told, and was going to be tossed In the trash. My buddy picked it up at a yard sale with a SX-550 and PL-510A. He wanted the receiver, sold me the turntable and was going to toss the cassette deck. All from the...

audiokarma.org

 

[MrCrabs]

Thanks radiokom! I just finished reading the thread and some good info. On my unit, I can watch the motor slow and run out of power until finally coming to a halt. That being said, I have not rejuv'd the idler so I'll add that to the mix and see if we can get this unit fully functional. Thanks for the info and let the sounds of your gear fill you with joy!

 

[radiokom]

Thanks radiokom! I just finished reading the thread and some good info. On my unit, I can watch the motor slow and run out of power until finally coming to a halt. That being said, I have not rejuv'd the idler so I'll add that to the mix and see if we can get this unit fully functional. Thanks for the info and let the sounds of your gear fill you with joy!

You should not try to "rejuvenate" anyway. It is myth, rubber can be only replaced, not "rejuvenated". But if motor stops it can be mechanical or electronic problem. Try to leave motor in ff mode without cassette for few hours. But lubricate it first. For this deck sewing machine oil will be good enough I believe.

 

[MrCrabs]

Thanks, I'll give that a try.

 

[gadget73]

If its a dc motor, can you hang a volt meter on it to verify its getting proper voltage and not just dropping for some other reason?

 

[MrCrabs]

OK radiokom, you sent me back to the drawing board and I reviewed my entire rework trail. I discovered a mechanical interface I did not lubricate; see photos. I use clock oil for mechanical connections... love the needle precision applicator and the oil viscosity as it needs to be held in suspension by surface area tension... but that's for another forum on a different site. The control rides vreically up and down on an expanded slot thru the mounting frame. Apparently there was too much friction at that point and once I oiled the section and mechanically exercised the joint, the unit worked as intended.

Thanks for the assistance and making me retrace my steps. Peeves me that I overlooked this connection and wasted time searching for a motor but as they say, live and learn... may eventually change it out but if it ain't broke, not going to fix it. That all being said, gadget73, I am going to throw my DMM across the terminals to confirm the motor is receiving proper voltage.

Adding some pics for reference and benefit.

Thanks for the swift assistance.
MC