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Pioneer CT-F9191

stuckinthe70s

stuckinthe70s

Active Member
Got a question for anyone who has experience working on Pioneer cassette decks. I just replaced belts and tires on my CT-F9191, that all went well but it still has an issue. When running in rewind, it starts out at high speed like it should, but then very gradually starts slowing down. Before it gets to the end of the tape, it will stop running all together. It does however run fine in fast forward.

During rewinding, if I look down into the transport at the spool end of the ff motor, I can clearly see that it's not slipping, the motor just slows down until it stops, as if it's run out of guts. Just for reference, I also replaced the pulley on the ff motor, and while I had it off, I gave the motor one small drop of oil.

I disassembled the transport again tonight just to check things out, and everything else appears in order, I didn't find anything that seems to be tight or loose. I'm suspicious of the motor itself, but why it goes in ff mode and not rw, I don't know. Does this sound like the likely culprit, or should I look for something else? Anyone with experience please let me know. I'd like to get this deck operational again to see what she'll do.
 
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Well, first I would get a service manual.

Then I would measure the voltage across the motor as rewind was progressing, to see if it was constant. If it IS, then I would measure the current draw of the motor through the whole process.

I would also use my finger to try and judge if the motor is loosing oomph, or the load is getting worse.
 
Ok, this is a common problem, and this thread discusses it in depth.. to avoid repeating myself, PLUS it has excellent pictures.

here is another thread

This is rich's thread about re-capping a ct-f1000 and the stuff about ff/rew starts on page 4, and the 1000 & 9191 have almost identical ff/rew mechanisms. A very illuminating thread fragment.

The bottom line is that the part pictured below must spin freely on the metal shaft without binding, when the deck is not in FF or REW (the neutral, centered position.) Just the friction from the side of your moving finger should yield rotation that continues until your finger looses contact with it.

I have a permanent, non-glue fix in mind, but the way things are going, if I get to developing it before 2008 I will be surprised. AND I have two decks to do that on.

edit - the non glue fix took until 2010, here it is http://www.audiokarma.org/forums/showthread.php?p=9035925
PM me for commercial / shipping details...

attachment.php


and if you are not sure where that part is, it is the part with the blue dots in this drawing of the transport.
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Yes, I have wanted to get my hands on a dead FF/REW motor to open it up and discover the details. I just can't bring myself to open a working one, even though I am relatively good at "watchmaking" type operations.

Someday I will find a really dead one...

I don't remember if the motors that have an adjustment screw / hole in the rear center are an electronic or mechanical (governor) speed adjustment. I do know those motors are just fed DC straight from the power supply.
 
First of all, thanks to those of you who've provided info and links, AK is such a great site full of helpful people, I just hope it can remain that way for a long time.

Ok, I have the service manual, I actually just got it last week. I also have a pdf copy that I downloaded from the Pioneer manual site, and it is nowhere near complete- the pdf copy has a total of 17 pages and my original paper copy has 93 pages. I'd love to be able to scan it all and upload it to the manual database as a way of giving back for all the help I've gotten here. It will be a major job of scanning, I'm going to try and get it done sometime, it will just take a while.

So last night I checked the voltage to the ff motor, in ff mode it showed 12.17V and held steady there, in rewind it had 12.05V and was steady, even as it was slowing down. I don't have a meter here to check the current draw, but I'm now pretty sure the problem is with the ff idler, as was indicated in this thread. Last night I opened up the transport for the second time(I'm no longer intimidated!) and removed the idler to have a look. What I first noticed was that the idler would not free spin, it wasn't really tight, just not as free as I thought it should be. I removed the clip and plastic washer on top, and then it would free spin easily. I put it back together, and of course nothing changed. I'm going to pull it apart again, I don't fully understand the clutch part of it and how it's supposed to work. I didn't notice any cracking of the plastic, but then I wasn't inspecting it for that.

I probably won't get to it anymore tonight, but am planning on tomorrow evening. I'll keep you all posted here of my findings and if I come up with a fix. I haven't quite gotten through all the links yet, I'm still reading. Good stuff so far, and thanks again to all who contributed!
 
After removing the FF idler for the 3rd time, I'm still not sure where my problem is. The idler assembly is really not tight on the shaft, the only resistance seems to be from the assembly against the plastic washer on top, due to the very bottom spring pushing up on it. What I have found now is that the only problem is in rewind mode towards the end of rewinding- that is, when the takeup spool starts getting full, it slows down. If I flip the tape over and start rewinding again, it goes like hell until that spool fills up, then gradually slows down to a crawl, and just before all the tape is rewound she'll finally stop. In FF it goes fast from start to finish. I've tried this with numerous tapes, 60 or 90 min, all with the same result. I'm puzzled.

So I decided to put the deck back together with the idler the way it is, to give it a test run and see how it works otherwise. Something else strange is going on with the sound. When playing tapes that I had previously recorded on other decks, there is a loss of high frequencies that sounds similar to using dolby on a non dolby recorded tape. And yes, I cleaned the heads, and they look in good condition. However, if I make a recording on the 9191, it sounds great played back on the 9191, but playing that tape elsewhere such as in the car, the high frequencies are boosted to the point of making my ears bleed. It seems like the bias is way off somehow, or just generally confused. Do any of you have an idea what might be causing this? I know some tape decks have issues when playing recordings on other decks, but this is way extreme. And I have no way of knowing if someone else previously messed with the bias settings and got it all f----d up. Any ideas anyone has would be greatly appreciated.
 
Don't chase your tail. Work on one issue at a time. One thing to look at is the belts. If one or more belts are too tight, it will cause problems similar to what you discribe. Mayb e try putting the old belts on and see how it acts, them, you can put them back on one at a time. Leave the capstan belt alone, as it is not part of this problem. The belts in question are the ones from the motor that drives the FF function to the reels. That is the path to check.

Rich P
 
Don't chase your tail. Work on one issue at a time. One thing to look at is the belts. If one or more belts are too tight, it will cause problems similar to what you discribe. Mayb e try putting the old belts on and see how it acts, them, you can put them back on one at a time. Leave the capstan belt alone, as it is not part of this problem. The belts in question are the ones from the motor that drives the FF function to the reels. That is the path to check. The bets associated with the counter and motion sensor cound cuase problems as well, but not likely.

Rich P
 
pustelniakr said:
The belts in question are the ones from the motor that drives the FF function to the reels. That is the path to check.

Rich P
Click to expand...
Rich,

The 9191 doesn't have any belts associated with the FF/rew function, just tires. And my old spool to motion sensor belt was loose enough that it slipped quite a bit so I doubt that would tell me anything.
 
Then you will have to focus on the FF/REW idler, or the motor pulley. something is slipping or binding. You will simply have to find it.

Rich P
 
Just got one of these...

Minty. Plays, no FF or REW. Have not taken it apart yet. fixed up a CTF 1000 and got the bug, Really want a 3 head deck. Got an CTF-850 coming. The 9191 is so pretty though but I am getting too many cassette decks.. May pick your brain. Saw the post on taking motors apart. The AC motor in my TEAC is sooo easy to take apart. Belts are a snap to. Prefer these older TEACs and have said. Damned bug bit me for a nice big Pioneer wth those damned DC brush motors:thumbsdn: Oh well. The CTF 1000 I fixed made great taoes:thmbsp:

Eric:music:
 
Got lucky on mine.....

Thought I would have pick your mind on getting back my FF and REW. I learned how to fix these without buying new tires. Fixed up a CTF 1000 three head deck with the same setup. They use a motor is the center for Ff and REW. At first it looked hard to get it apart. After looking there are only three screws holding the motor in place. Came out easily. Had Marilyn get me a small emery board and sanded off the glazzed surface on the rubber wheel on the motor shaft. Learned on the 1000.

Bought the 9191 on Ebay. Very nice deck. Seller did not know cassette decks. It also had not FF or REW. Had some time after work and cleaned the wheel on the motor shaft with and ememry board. Took denaured Alcohol to the wheels on the tape hubs and cleaned their surfaces. Put it back togather and FF/REW are back in full force.

I am lucky my 9191 did not slow down in either direction:banana: Cleaned some of the controls tonight and did a test recording. Works well. I would not want to take a DC motor apart--even with the post shown here. These motors are a pain to work on. My Teac is much easier with its AC motor. Its like their RTRs. Take it apart and oil it. No brushes to mess with.

Said I never would get another Pioneer. Got hooked on three head--like the CTF 1000 and big Pioneers. Got 9191 fixed. Its minty. Got a CTF 850, a three head deck coming. Will probably keep the 850 and sell my 9191. Getting too many cassette decks around here. Went through this with RTR TEACs.

Hope you find the cause of whats causing your 9191 to slow down. Generally dont like working in cassettes. My hands are big and the area is small:tears:

Eric:music:
 
This didn't need it...

markthefixer said:
Eric:
did you deoxit the rec / pb switch in the lower chassis?
Click to expand...

though I first saw a sticky REC/PB on a Pioneer. It makes the deck act wierd!!! Had a nice TEAC 460 that had that problem. This 9191 seems OK. Put contact cleaner on the line in,mic, and output pots. Ran real nice. FF and rewind working well now. Records nice. Will take a look at the incoming three head Pioneer 850. One will likely go. If the 850 is any good it will be a tough choice.

The 9191 has a nice transport. It handles tape well. We will see.:scratch2:

Eric:music:
 
Same issue but with ct-f1000

A couple of months ago I got my hands on a ct-f1000 for the first time.
However it was dead at that point. After replacing one of the micro switches the motors started to work and with new belts in place things started to move.
So far so good. At least I thought.

The rewind/fast forward slows down and stops before the tape is fully re-winded.
Just like the first discussion in this thread. The motor seems strong when I try to stop the pully with my fingers(but it is difficult to say if it is enough), the voltage over the motor is roughly 13volts, I can see a small drop as the motor slows down, but it i still close to 13. There is no slippage between the wheels when it stops and the clutch is not activated.

Could this be a clutch problem? The assembly on the axle is quite easy to move, however, it does not free spin. There is a significant friction between the friction pair in the clutch.

I can´t figure out why the motor seems strong but still it is not able to rewind the tape to its fully. Any ideas?

Thanks!

regards
Thomas
 
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New test

I did a new test last night after reading a post stating that new belts can have a negative impact on the drag in the system. I removed the belt between the counter and the autostop mechanism. This belt was quite stretched. This definitely had an impact on the rewind speed. What also makes a different is when I lift of the spring loaded brake from the left wheel.

Is the motor not strong enough? Or is the clutch building up a force that push the total torque over the limit of the motor? Is the motor just as strong as necessary and have no margin to handle extra load?

Thanks!

Regards
Thomas
 
You likely have a problem with the fast mode reel clutch. They split internally and add drag to the system. It is fixable.

Belts are all likely in need of replacement at this age as well.

Good luck,
Rich P
 
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Thanks for your response Rich!

All belts have been replaced with wjoe belts. I also replaced the ff/Rew pulley.

The clutch seems fine to me. The clutch package do stay together when I compress the "outer" spring and should not affect the overall assembly and how the wheels behaves around the axle. Or do I miss something out? My impression is that the "outer" spring press the clutch assembly in a way that some resistance is developed. Is there anything inside the assembly that might be "old"(the well known crack excluded) so a higher friction than first intended has developed?

The motor is easy to turn and the take up reels(is that the name?) turn easy.

As information, I have read all the threads regarding the clutch issue, but I do not see this is the problem. But I have not yet disassemble the clutch(the clutch is frightening me).
Thanks

Regards
Thomas
 

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