Onkyo 2050 project still "jumping" tape

[shacky]

I'm not sure how to describe what's happening with my Onkyo. I've replaced the idler tire and pinch roller. This is my first attempt at this so I very well could be missing something.

for the most part the deck plays and records fine. Sound is excellent to my untrained ears. But every now and then I hear the tape clicking, or clapping. Like it's get hung up then cathing up. It's happened on 3 different Maxell XLIIS 90 minute tapes so I don't think it's a tape issue.

It's odd as it happens at random. I'll hear the noise and being attantive I'll hear it a couple more times. Once I could even see the tape walking in the deck. Then it doesn't happen for a whole side.

Think it could be something like Pinch Roller spring tension being too loose or too tight? I didn't change it.

http://i137.photobucket.com/albums/q227/shacky1973/IMGP1538.jpg

http://i137.photobucket.com/albums/q227/shacky1973/IMGP1537.jpg

http://i137.photobucket.com/albums/q227/shacky1973/IMGP1498.jpg

[Mopic5]

Hi Shacky,
This may be a case of the blind leading the sighted ('cause my Onkyo restore has been less fruitfull than yours), but maybe my questions will get others to chime in.
When you say, "Once I could even see the tape walking in the deck," do you mean that the tape is paying out at the capstan without take-up? If so, sluggish hub motors sometimes can be loosened up by multiple excercise periods of FF & REW.
Another tac maybe to see whether these Onkyo TA-20XX decks are ultra transport (cassete design) sensitive. Will the problem repeat on a cassette other than the Maxell XL-II?
For what it's worth.
- Mario

[shacky]

What I saw was the cassette shell itself moving - more on right side - within the chamber. It makes a clicking sound I can hear across the room - and I don't have the best ears. Something definitely not right.

I thought maybe it was just one cassette having a rough spot or something. But when it happens to others that I haven't heard this problem with on my H/K, makes me feel it's still something a little out of whack with the Onkyo drive mech.

Maybe it is the tak up motor. It plays pretty well and I don't hear the music slowing when it happens. But I'm afraid it's going to eat a tape one day.

[Fred Longworth]

Make sure that the replacement idler tire has the correct diameter.

* * * * *

Disconnect the reel motor and hang an ohmmeter across it. Let's say (just for purposes of our thought experiment) that it has 30 ohms of resistance. Now turn the pulley very slowly through an entire 360-degree rotation, noting how the resistance varies as you turn. Does it hover fairly closely around the nominal resistance value? Or does it have one or more points where it dips precipitously?

If it dips significantly, you have a commutator failure. Small amounts of chaff from the commutator have gotten lodged in the slots between commutator sectors "shorting" the motor winding(s). In some instances this can be "cured" by disconnecting the motor entirely and zapping it with 12-15 volts from a regulated power supply for 30 seconds.

* * * * *

This is the same transport used on the Nakamichi CR.. series.

* * * * *

Also, look toward the freedom of movement of the idler arm assembly. Does it swing effortlessly CCW toward right reel or CW toward left reel?

* * * * *

Best,

Fred

[shacky]

Fred,

I think this is the idler tire I ordered:

32-6375 - Onkyo Type Idler Tire
IDLER TIRE FOR ONKYO ASSEMBLY 15.5MM X 10.6MM X 2.20 Replacement Type Idler Tires, Type: Onkyo, Outer Diameter: 15.5 mm, Inner Diameter: 10.6 mm, Width: 2.2 mm, Quantity: Minimum five pieces

I'll try taking motor out and test as you outline. I know this isn't a top of the line deck but it's the model my wife gave me back ~ '80 that has a lot of sentimental value. Plus I really like the looks of this unit.

[shacky]

Fred,

Telling me this is same as Nak CR drive led me to look up that idler tire size which is:

IDLER TIRE ONKYO FOR HARMON KARDON AND KENWOOD REEL MOTORS Replacement Type Idler Tires, Type: Onkyo, Outer Diameter: 14.22 mm, Inner Diameter: 9.6 mm, Width: 2.06 mm, For Use with: Harmon Kardon and Kenwood Reel Motors, Quantity: Minimum five pieces

So idler tire I put on is 1.28mm larger. Think that makes a difference?

[shacky]

Found 2 things that may be giving me trouble with this deck. First I looked at the pinch roller in action - with mech out where I can see it. Rubber roller is wobling :tears: The replacement roller i ordered had wrong axle size so I had pealed off the rubber and put it on my old hub. Tried as I might to get it on even aligning this by eye obviously not good enogh. This in itself may be route of my problem.

Second, when removing mech I noticed a loose wire from remote control input section. Here's a pic though out of focus there's a red wire with bare end very close to bottom plate. Don't know if this could be part of my problem.

http://i137.photobucket.com/albums/q227/shacky1973/IMGP1913.jpg

Before disassembling i tried one more recording session. While I didn't get the clicking it stopped twice. Both times there was a curle of tape coming out of the cassette by pinch roller. Luckily it stopped and did't chew up the tape.

[shacky]

Hadn't had time or patience to work on this till today. Tired of looking at it all apart :yes:

Took mechanism out but didn't check the motor as I can feel with my fingers that it's quite strong. Played with the pinch roller and I think I had bent the brackect a bit as the roller was a tad too sloppy.

Resoldered that wire that was hanging from remote control dodad. I'll bet anything that's what was giving me the intermitent "jumping" of take up motor. But I could be wrong.

Have played one side of 90 min tape with no problems. Keeping my fingers crossed.