OTARI MTR-10-2 tension problems

Thanks for the advice. I can't find anything in my manual relating to those sensors, do you happen to remember what this was called by any chance? I'm wondering if my manual is complete as I downloaded it in two different sections.
 
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So I've been slowly communicating with a guy who has experience with these decks but now I haven't heard from him for a couple of days. He correctly identified my swing arm problem as a leaky dash-pot, which I fixed. Unfortunately the problem still exists. I've included two links to youtube videos showing what the deck does upon playback with no tape and what the repaired swing arm now does. My big problem here is I can find nothing in the manual for adjusting reel tension other than what I've already tried. I've read that if you don't use these often enough the magnets in the motors go out or something, I don't know. I'm at a loss here currently. Here are the videos I spoke of, if anyone cares to watch and diagnose.

https://youtu.be/YzTwN7eEj6E

https://youtu.be/x8DsCtciMnY


Thanks again for any tips towards any direction.
 
hahah I'm in the habit of playing things through. If I have to turn both spools of a cassette with paper clips, I do it. That is odd, but it's like stretching your legs. A machine that's been in the garage for 70 years needs to stretch it's legs and try to shake out the kinks. It sounds less probable with logic control, but don't be too sure.
 
There's sone truth to that. I had a console I picked up that had been sitting for a while. Boy it was funky for a bit. I ended up cleaning it properly, but just a couple of days with some juice running through it cleared up 50% of the gremlins

To the OP, sorry I have no words of wisdom to your specific situation. But I'm sure with the help of people that have some knowledge, you'll get it sorted.
:D
 
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So I've been slowly communicating with a guy who has experience with these decks but now I haven't heard from him for a couple of days. He correctly identified my swing arm problem as a leaky dash-pot, which I fixed. Unfortunately the problem still exists. I've included two links to youtube videos showing what the deck does upon playback with no tape and what the repaired swing arm now does. My big problem here is I can find nothing in the manual for adjusting reel tension other than what I've already tried. I've read that if you don't use these often enough the magnets in the motors go out or something, I don't know. I'm at a loss here currently. Here are the videos I spoke of, if anyone cares to watch and diagnose.

https://youtu.be/YzTwN7eEj6E

https://youtu.be/x8DsCtciMnY


Thanks again for any tips towards any direction.
The left hand sensor arm should control the speed that the spooling motor turns, so follow the path from the control output fitted to that arm. It may be a vane arrangement or a pot. The motor runs first off because it is common in tape circuits to apply a startup boost when you first go into play to stop the deck throwing a loop.
 
Have you read and understood the manual? Page 5-7 shows how you can run a test program to check the motor tensions. Do this test, which will tell you right away if you have a motor problem or a tension sensor problem.
 
Yeah I have a manual, though I believe it to not be complete as the exploded view isn't included. I have ran the tension adjustments on 5-7 and also the brake tension test on the previous page. All things there check out. I'll try following the control from the arm and see if anything looks suspect. Thanks for the help everybody!
 
The fact that the tension tests work fine suggests that your motors and basic drive circuits are working fine. Your problem is unusual, so I am just speculating. When you load a new reel of tape on the MTR-10, for the first few turns the computer monitors the rotational speed of the supply and take up reels and the linear speed of the tape to calculate how much tape you have on each reel. Once it does that, it sets the internal tension for supply and take up, and continuously adjusts it as you further handle tape. I suspect that the computer is not able to calculate the proper tension for your supply reel and it is setting the wrong tension or using a default that is causing you problems. The fact that it goes into fast forward after you stop from reverse play reinforces that. Your roller sensors' phase adjustment seems OK from what you describe. I would look at the output of the small sensor board mounted directly to the supply motor assembly and also for the take up assembly to make sure it is sending pulses when the reels are turning. I would also check the reel size sensors to make sure they are functioning as this could provide bad data.

I cannot find anything about the tach sensors in the manual except in the schematics. I will include a photo of one of the circuit diagrams below. Hopefully, this will give you enough information to check the sensors. You can run the deck while it is open, and check the outputs of the sensor boards with an oscilloscope. I hope this helps.

Otari Reel Tach.jpg
 
Mark, thanks so much for all that info. That sounds very likely to be the source of my problem. I'm unfortunately on tour right now and won't be able to test that out but as soon as I get home I'll jump into that and post back. Thanks again for the info and the quality scan!
 
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