Author Topic: NAD 6050C repairs  (Read 300 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...