Author Topic: NAD 6050C repairs  (Read 555 times)

Offline Aqualung

NAD 6050C repairs
« on: November 29, 2018, 06:51:56 PM »
I am trying to fix a NAD 6050C CTD.

All belts perished, but I cleaned up all the goo, and fitted new belts.
Motor spins perfectly, as does main flywheel.
FF and REW work perfectly.

However, it does not play: when PLAY is pressed, the tape head mechanism starts moving up, but does not go up far enough to let the play wheel come down and engage with the right capstan. It needs to move up about another 10%.
I have disassembled almost every small bit in the play mechanism, removed old hardened grease, and reassembled.
No change.
The upwards movement of the tape head mechanism, BTW, is not controlled by any belt, but by the gears of the main flywheel and a plastic (nylon) "lift-gear".

What am I missing / what should I look at next? Any advice greatly appreciated.

Johan

I love music - analog and digital. Even listening to the Blues makes me happy. During the day I coach and counsel, after hours I indulge in my second passion - listening to vinyl and restoring turntables. Some I keep, some I sell...

Offline Bruce M

Re: NAD 6050C repairs
« Reply #1 on: November 30, 2018, 09:49:17 AM »
Got a non-working NAD 6050C in CT.... will swop for a piece of vinyl!

Only kidding, you can have it.

Offline Rick

Re: NAD 6050C repairs
« Reply #2 on: November 30, 2018, 11:12:04 AM »
Is there a potentiometer attached to the one gear (Nakamichi style)?

If so then the gear movement is controlled by another pot elsewhere or a microswitch. The problem sounds electronic rather than mechanical to me.

On some decks there is a cam hidden behind a plate that controls the head travel they usually have 4-5 positions.

Offline Aqualung

Re: NAD 6050C repairs
« Reply #3 on: November 30, 2018, 01:41:27 PM »
Is there a potentiometer attached to the one gear (Nakamichi style)?

I don't think so - have not found it yet.

On some decks there is a cam hidden behind a plate that controls the head travel they usually have 4-5 positions.

Am looking for something like this, have also not found it yet. But I am still staring at it... :-)

Thanks for the ideas!  :thumbs:
I love music - analog and digital. Even listening to the Blues makes me happy. During the day I coach and counsel, after hours I indulge in my second passion - listening to vinyl and restoring turntables. Some I keep, some I sell...

Offline Aqualung

Re: NAD 6050C repairs
« Reply #4 on: November 30, 2018, 01:42:02 PM »
Got a non-working NAD 6050C in CT.... will swop for a piece of vinyl!

Only kidding, you can have it.

Thanks Bruce, have PM'd you.  :thumbs:
I love music - analog and digital. Even listening to the Blues makes me happy. During the day I coach and counsel, after hours I indulge in my second passion - listening to vinyl and restoring turntables. Some I keep, some I sell...

Offline Aqualung

Re: NAD 6050C repairs
« Reply #5 on: December 04, 2018, 06:53:07 PM »
Many thanks to Bruce for the donor machine.
I combined many different parts from the 2 machines, until I had a mechanically-working machine.
But: with very distorted sound!
Then I transplanted the erase and playback/record heads, and got perfect sound.
Also found the problem with the previous set-up: a crack in the black plastic head carrier base that, under strain when lifted,
did not allow an adequate rise.
Everything now works well, but there is a playback speed issue.
Will try and adjust the motor speed tomorrow, using a test tone, and if that does not work, transplant the motor as well.
Getting there!  :thumbs:
 

I love music - analog and digital. Even listening to the Blues makes me happy. During the day I coach and counsel, after hours I indulge in my second passion - listening to vinyl and restoring turntables. Some I keep, some I sell...

Offline Aqualung

Re: NAD 6050C repairs
« Reply #6 on: December 06, 2018, 03:18:16 PM »
Speed adjusted, recording string tension adjusted and everything now 100%.
Thanks for the help and advice.  :thumbs:
Mods can please lock.
I love music - analog and digital. Even listening to the Blues makes me happy. During the day I coach and counsel, after hours I indulge in my second passion - listening to vinyl and restoring turntables. Some I keep, some I sell...

Offline kritzingerf

Re: NAD 6050C repairs
« Reply #7 on: December 27, 2018, 02:48:12 PM »
I have a 6050C with exactly the same issue... head carrier not lifting high enough...  That black plastic bit breaking is a fairly common issue with these, it seems. it was fairly easy to find the symptom, and solution in the interweb...

However, I now have a different problem...  it seems that the plastic molding that forms the inside of the cassette mechanism, is distorted.  The result is that it pushes against the gears and insides of the mech.  I have tried various things to improve this, but alas, no luck.  WHEN I get it to play without auto stopping, it sounds quite good...   but I can simply not get it to reliably run...

I am beginning to wonder if it is not perhaps a belt issue, something like slightly stretched belts?

Where did you get replacement belts to repair your deck?  I have a Harman Kardon which also needs a belt or 2

And when that is done, a Technics CD player which I still need to open, and see what is amiss with it. it wont eject...  It has a Tolla van der Merwe CD inside, and I have listened to his stories enough now!


Offline Aqualung

Re: NAD 6050C repairs
« Reply #8 on: January 01, 2019, 06:23:01 PM »
I got all the belts I needed for this deck from BC Electronics on Voortrekker Road in Parow, Cape Town.
Another source is TV World in Kraaifontein (if you are in CPT).
I love music - analog and digital. Even listening to the Blues makes me happy. During the day I coach and counsel, after hours I indulge in my second passion - listening to vinyl and restoring turntables. Some I keep, some I sell...