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Pioneer CT-F 1250 Reel motor fails to take up tape

oldvinyldude

oldvinyldude

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Looking for some clarification on the health of the reel motor. The capstan motor runs fine.

After replacement of the 3 belts and idler rubber, the deck will FF and REW, but when play is attempted, the take up spindle fails to turn. I have observed, with the case off, that the motor runs fine in FF\REW, and the tape moves accordingly.

In play mode, I can observe the brake lifting in play mode, so that is not stopping the motor.

My reading has indicated one primary culprit may be dead spots on the motor, and I may be able to disassemble, clean, burnish, and replace. Before I attempt this, I wanted some clarity.

My question: If the motor runs without issue in FF\REW situations, and only stops during play mode, am I still looking at dead spots?

I have observed the motor attempting to spin on occasion, when selecting Play, but mostly, it never moves in Play mode.

I know a replacement motor may be used, but I lack the skills to modify calibrations to make it function correctly.

Before I attempt a rebuild, I wanted some advice.

Thanks
 
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You might be able to clear the problem by the following method:
  1. Power up the deck
  2. Push in the tape presence sensor (on the lower right of the tape well)
  3. Activate "Play"
  4. Let it run for 48 continuous hours
Check operation after the above, and see if the issue clears up or improves significantly. Disassembling the motor for rebuilt is a bit of a risk. If you can clear it by running the deck, all the better.

Once clear or corrected, you really need to regularly and repeatedly actuate all user controls, and operation modes (record, play, fast, etc.). You also need to use the deck regularly.

Good luck,
Rich P
 
Also, if you rebuild the motor, you will need to make sure that the small belt from the motor to the next pulley is not too tight. Otherwise, similar problems can occur.

Rich P
 
Thanks folks

Seems my motor observations have changed. I was getting decent FF\REW, but this has now deteriorated. It's clear that the motor is in poor shape.

I have removed the motor, and will attempt the rebuild. If someone here is up to the task, please PM me. I will take my time, perhaps not attempting it for quite some time. I wish I had 30 year old hands, instead of 60.....
 
Another question:

So that I don't have to go back in, would it be beneficial to run the motor on a 9 vdc power supply, for some hours, before reinstalling?

Of course, this would not load the motor like hours in a "play" condition.

Perhaps this might be worse than running in with a load?
 
I would not likely hurt, and could help some, but I would use 8v. Make sure the small belt that goes to the motor pulley is not too tight when you put it back together.

Rich P
 
Motor is out of case, but now I am waiting on a set of tiny hex wrenches, so I can remove the pulley. My smallest one on hand is 1.5mm.

I don't have a DC power supply, so I am thinking 6 AA batteries, using NiMh cells at 1.2v=7.2v. Is this OK?
 
I was able to disassemble and clean\burnish the motor, and it has been reinstalled.

The motor looked to be pretty clean including the contacts that the brushes ride on-not as bad as the pics I have seen Rich and others post.

It now is running a FFW continuously, and after 15 minutes it's still running (it would stop a couple of minutes in-before the rebuild). When I grab the spinning motor pulley, it feels nice and strong, and similarly, when I grab the spindle as it's running in FFW, it has lots of torque.

However, I still fail to get take up when play is engaged. I also note, that there is no slack takeup when a cassette is first inserted-I believe this is a design element-to take up slack upon cassette insertion).

When I measure voltage across the motor wire binding posts, I get 12v on FFW, and 7.4 when play is engaged. I have barely any electronic troubleshooting skills, so I am worried that it's an electronic issue, and not the motor.

I will let the unit run in FFW for the rest of the day, and test again, but I am fearful that the issue is not the motor.....
 
Two microswitches are in there. One to detect the record tab and one to detect the tape presence. They will become dirty over the years and should be replaced. My thread on restoring the CT-F900 transport should help you find the switches and other concepts. DeOxit does not work on microswitches, since such requires a bit of wiping action to clean. The tape presence sensor must be good and properly adjusted, indicated by a bit of light reverse torque when putting a tape in, to take up any slack (bad for dual capstan decks).

A when a reel motor rebuild "takes" the voltage across it is 8v or better in play. Make sure that the motor from the reel motor to the 1st pulley is not too stiff/tight, or you will have problems.

Rich P
 
After running several hours in FFD, no stoppage of motor, so it's seems good now.

I looked up the switches in the thread, and have them in my basket.

I note that the left switch will activate the solenoid to it's left for 1.5 seconds, then release it. Right switch is activated by pin on right side of cassette well, which I taped over to keep it activated during the multi hour FFD test.

Each time I hit play, I get a very momentary take up spindle movement-perhaps 1/10 to 1/4 second, then no further movement.

Seems both switches are working, but I will replace anyway, if advised.
 
Switches replaced-no change.

I disassembled the take up spindle, cleaned and replaced lube, fluffed up the felts, reinstalled, and it will spin for a bit longer in play mode, but still stalls.

Motor (rebuilt), shows good torque when running on 7.2v source, outside of deck.

I am going to disassemble the idler roller and clean. Tire is new.
 
Last edited:
Success!

Decided to check the idler assembly. Disassembled and cleaned, and in the process, discovered the drive belt was not riding in the pulley slot. It was riding in front, effectively reducing tension so that the spindle would not have sufficient torque to move the tape during play mode.

Once it was moved to it's correct place, and I reinstalled the brake plate and the upper spring loaded guide (must have done this operation 5 times-got pretty good at it), I have play and no tape spill.

Perhaps the motor rebuild was not necessary-the motor did not look bad when I opened it up, but I am glad it's done. Good for many more years. Can't say enough positive things about Rich P's instructions and cautions.

Thanks!
 
Another super deck saved from becoming landfill, nice work you guys. I bought a 1250 new in '79 and used it for many years, now my kid owns it and a ZX-7 and won't give either one up.

Thanks for your knowledge Rich!
 
Reviving my old thread here.

After restoring the reel motor to operational condition, I was in the middle of trying to calibrate the deck to a tape, and the motor failed again. This prompted a quest to find a replacement, and I tried 2 motors-and got mixed results and basically stopped trying. I went back to the original motor, tried disassembly and reassembly 3-4 times, and burnishing the contacts again. It would run for maybe an hour or two-no load-just connected to a power supply. Put aside again.

A week or so ago, I pulled it apart again, after someone on a forum here reminding another member, to clean the slots on the rotor. I carefully did this, and one slot in particular was pretty full. Reassembled and it ran for about 24 hours. Pulled it apart again, and removed more carbon from a slot or 2. Reassembled and it has now run for 3+ days. Initially, at 8.4 v it was drawing about 60-70ma (unloaded). After a few hours, it had settled to about 20ma-a good sign, I believe.

Next step is to put it back into the deck and run it in FFD with not tape, so it has a light load.

I will update and hope for continued running! I also stretched the drive belt more strongly (I replaced it and was warned by Rich P. to stretch it-but perhaps not enough?)
 
I tried to save the reel motor on the 1250 that previously belonged to a_retent, but it had simply seen too much use - armature was very worn down and the brushes weren't healthy either. FF & REW were slower than I wanted to see even after several cleanings (2-3 minutes to go through a 90 minute tape) and it would take up the tape as it saw fit.

I was forced to replace the motor with the other one from the parts unit. The transplant was successful, but it would be nice if someone was able to figure out a replacement as I no longer have a spare and the deck does see moderate use (plus, I don't want to cannibalize another one of those beautiful machines!), along with the ZX-7 (thankfully that only has 20 hours or so since a complete overhaul).



-Jason



PS - In my case, the points were worn beyond cleaning additionally. I certainly don't have the equipment to correctly set one up with replacement points...pity.
 
pustelniakr said:
Also, if you rebuild the motor, you will need to make sure that the small belt from the motor to the next pulley is not too tight. Otherwise, similar problems can occur.

Rich P
Click to expand...
Sorry I'm a little late to this but I have also a take up issue. I have owned this 1250 since the mid 1980's. It was given to me by a friend who was having issues getting it repaired and he just gave up and gave it to me. Put in a tape and the take up wouldn't engage. I didn't really need it since I had just bought a Nak BX300 so I put it on a shelf. Recently I dug out the 1250 and decided to replace the belts. Ordered a kit from Vintage Electronics and I managed to soldier through the replacement and got it done. It worked and I got to hear this machine for the first time and I loved it. After a few hours of play the take up stopped. I read through this thread and decided to rebuild the motor. It just so happens that there was a spare motor with the machine. I had forgotten that my dad had replaced the motor when he worked in electronics repair. This was the old motor. I did the rebuild on that one and put it back in the machine and all seemed well. It was showing the voltages referred to in this thread for play and FF. After a few hours of play it stopped working. I did a rebuild on the second motor, tested it and let it run in with severa fast forwards and rewinds and it seemed good. This on also failed after just an hour of play. I removed the cover and removed the belt from the pulley. The motor runs strong without the belt and has what feels like good torque. I see where you mention issues if the belt is too tight. This one feels as though I have to over stretch it to get it on or off the pulley. Too tight? I'm not sure. How does one tell what too tight and just right is? On a 9v battery both motors spin right up strong. If the belt is too tight what is the best way to stretch it?

Thanks for listening
Brian
 
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