Technics SL B210 record player strange noise. - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Nickthedentist · 27th Feb 2018, 5:31 pm

...and then make it a slacker fit with a file, and glue it into position (instead of relying on an interference fit) to avoid a repeat performance.

Not my idea, someone clever here mentioned it recently.

Nick.

sobell1980 · 27th Feb 2018, 9:46 pm

Hi and good evening Nick. Thank you for your replies on my thread and also everyone else who has contributed. Can I refer you to post #6 In answer to your post #15. I had of course previously removed checked and span up the platter by hand . It was the first thing i did when i got it. It was then i singled out the motor was infact noisy without load which made me think it's a worn belt when it gains some slack around the motor pulley. I've done more videos to post shortly of various tests.

sobell1980 · 27th Feb 2018, 9:52 pm

Video of being spun by hand. No belt fitted. Please excuse my dog whining outside the door.
https://youtu.be/wNgqAGpb6SU

Video being spun by hand with belt on.
https://youtu.be/KnVxoZsCUpU

Motor running by itself again.
https://youtu.be/8LuMR6z07hI

Marconi_MPT4 · 28th Feb 2018, 8:29 pm

Hi,
Worn or seized bearings were very common on Matshushita motors in the early to mid eighties. We had a lot of customer complaints regarding excessive mechanical noise. Only three or four out of a batch of twenty replacement motors were sufficiently quiet enough to meet the published specifications.

There should not be any play between shaft and bearing, but wear of the latter into an ellipse produces the characteristic clunk when checked for movement.

One trick that might help is to rotate the motor body, if possible, moving shaft side tension to a different section. Depends on how the motor is mounted and space in the cabinet for this to work.

Cheers
Rich

sp10mk11 · 2nd Mar 2018, 7:18 pm

Hello I have repaired a lot of these noisy motors over the years, it is a standard 3 pole Dc motor except it has a magnet on the shaft and this drives a coil to produce a signal for the servo.
The problem is the plastic housing that holds it all in place can just crumble and fall into the motor creating the noise you describe and show, a lot of patience and superglue is how I have done them.
Good Luck
Gary

27th Feb 2018, 5:31 pm	#21
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,866	Re: Technics SL B210 record player strange noise. ...and then make it a slacker fit with a file, and glue it into position (instead of relying on an interference fit) to avoid a repeat performance. Not my idea, someone clever here mentioned it recently. Nick.

27th Feb 2018, 9:46 pm	#22
sobell1980 Octode Join Date: May 2011 Location: Bromyard, Herefordshire, UK. Posts: 1,241	Re: Technics SL B210 record player strange noise. Hi and good evening Nick. Thank you for your replies on my thread and also everyone else who has contributed. Can I refer you to post #6 In answer to your post #15. I had of course previously removed checked and span up the platter by hand . It was the first thing i did when i got it. It was then i singled out the motor was infact noisy without load which made me think it's a worn belt when it gains some slack around the motor pulley. I've done more videos to post shortly of various tests.

27th Feb 2018, 9:52 pm	#23
sobell1980 Octode Join Date: May 2011 Location: Bromyard, Herefordshire, UK. Posts: 1,241	Re: Technics SL B210 record player strange noise. Video of being spun by hand. No belt fitted. Please excuse my dog whining outside the door. https://youtu.be/wNgqAGpb6SU Video being spun by hand with belt on. https://youtu.be/KnVxoZsCUpU Motor running by itself again. https://youtu.be/8LuMR6z07hI

28th Feb 2018, 8:29 pm	#24
Marconi_MPT4 Heptode Join Date: Mar 2011 Location: Dorset, UK. Posts: 522	Re: Technics SL B210 record player strange noise. Hi, Worn or seized bearings were very common on Matshushita motors in the early to mid eighties. We had a lot of customer complaints regarding excessive mechanical noise. Only three or four out of a batch of twenty replacement motors were sufficiently quiet enough to meet the published specifications. There should not be any play between shaft and bearing, but wear of the latter into an ellipse produces the characteristic clunk when checked for movement. One trick that might help is to rotate the motor body, if possible, moving shaft side tension to a different section. Depends on how the motor is mounted and space in the cabinet for this to work. Cheers Rich __________________ To an optimist a glass is half full; a pessimist half empty; an engineer twice as big as need be!

2nd Mar 2018, 7:18 pm	#25
sp10mk11 Octode Join Date: Feb 2009 Location: Cornwall, UK. Posts: 1,275	Re: Technics SL B210 record player strange noise. Hello I have repaired a lot of these noisy motors over the years, it is a standard 3 pole Dc motor except it has a magnet on the shaft and this drives a coil to produce a signal for the servo. The problem is the plastic housing that holds it all in place can just crumble and fall into the motor creating the noise you describe and show, a lot of patience and superglue is how I have done them. Good Luck Gary