JVC HR-S9850 fast FF/REW & Stop problem

[Thermaltake]

Hi, when tape is doing fast FF or fast REW and I hit stop, right reel stops almost instantly, and left reel is still spinning for second or maybe half second. And you can hear that crackling when tape stops and it wrinkle a bit on the side where pinch roller is I think before it. Then I do a little REW or FF to tight the track back because in that moment it became loose on pullies. I can't find out what's going on and how to fix it, I tried to replace that left brake arm but still same, everything is clean in vcr, new pinch roller, belts, felts. Any idea what this problem could be ?

Here is video of it maybe it will explain better.

https://i.imgur.com/SLDyabt.mp4

[CaptureCraft]

There might be a stopper for the brake arm, which could be adjusted. I had a case when I had to cut out almost in half of the stopper to make the brake arm to reach the proper position.
Or, maybe, just make the brake pad thicker.

[Thermaltake]

There might be a stopper for the brake arm, which could be adjusted. I had a case when I had to cut out almost in half of the stopper to make the brake arm to reach the proper position.
Or, maybe, just make the brake pad thicker.

I have one good S9850 also and I tried to replace right brake arm from that one to bad one, and same thing. I compare everything from good one in bad one everything is in the same place

https://i.imgur.com/EXambzP.jpg


there is just one screw that I tried to adjust and it's labeled in manual as adjustment screw, but however I turn it, it's the same. I circle it red.

https://i.imgur.com/fSoWw2S.jpeg

[CaptureCraft]

Your second image doesn't exist.

[Thermaltake]

Sorry, link fixed.

Found out on other forum that black screw is to adjust back tension in play and record. So it has nothing to do with brakes.

[CaptureCraft]

Yes, that asymmetrical black screw controls how close the brake pad on that arm gets to the reel.
So, what was the fix?

[Thermaltake]

Yes, that asymmetrical black screw controls how close the brake pad on that arm gets to the reel.
So, what was the fix?

Vcr is not fixed link for image is hehe

black screw is not for brake adjustment like I wrote up.

[CaptureCraft]

Yes, that asymmetrical black screw controls how close the brake pad on that arm gets to the reel.
So, what was the fix?

Vcr is not fixed link for image is hehe

My bad.

black screw is not for brake adjustment like I wrote up.

Well, how do you think the tension is controlled, if not by a brake?
It's all on the picture you posted. The arm with the brake pad is controlled by the black screw, which moves the basic position of the arm a little bit closer or further away from the reel.

[Thermaltake]

Yes but it's not problem in that reel it's the problem in other reel as you can see on the video. This left reel is breaking ok, right one is stopping instantly and is causing the problem. And on the other reel there is no screw or any adjuster.

[CaptureCraft]

Yes but it's not problem in that reel it's the problem in other reel as you can see on the video. This left reel is breaking ok, right one is stopping instantly and is causing the problem. And on the other reel there is no screw or any adjuster.

Yes, I agree, that particular screw and the arm with brake pad are not part of the problem. I would say it was just miscommunication.
On the other hand, your description of the problem is a little bit confusing.
Does problem happen when you FF or REW or both?

[Thermaltake]

Yes but it's not problem in that reel it's the problem in other reel as you can see on the video. This left reel is breaking ok, right one is stopping instantly and is causing the problem. And on the other reel there is no screw or any adjuster.

Yes, I agree, that particular screw and the arm with brake pad are not part of the problem. I would say it was just miscommunication.
On the other hand, your description of the problem is a little bit confusing.
Does problem happen when you FF or REW or both?

Oh my bad, sorry.

Problem happends in both ways when doing fast FF and fast REW and when you stop it wrinkle the tape somewhere before pinch roller (that would be right reel) just at the top of the cassette. You can even hear on the video I uploaded that it cracked(wrinkle) when I press stop and see how the right reel stops almost instantly after stop is being pressed, and left reel is still spinning a bit. After that track on the pullies is loosen.

[CaptureCraft]

If the problem happens in both ways, then it is really hard to pinpoint.
Obviously, the leading reel stops before the driven one, but why?
Here are just some ideas as a starting point.
There is some grease on the reels or brake pads.
A week spring, which should engage the brakes.
Or there is a dry lubricant somewhere, which slows down the arms with brakes.

It might take a lot of time and effort to figure that out and result is not guaranteed.
You have to decide if it worth it.