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Guest Simonon

Sony WMD6C pro walkman rebuild

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Guest Simonon

 

Just finished rebuilding a dead Sony pro walkman. Hooked up at some stage reverse polarity which took out the DC converter and capstan servo chip. New belts and idlers and the unit is perfect. Very impressive sound on par with my Akai GXC760d. I measured wow and flutter after repairs and it is impressive for a walkman built in 1983. A great new plaything.505e6a7e9fe7939d9059fa84a87d117c.jpgd774d8dadf932724e62c869259a2f7e0.jpg6b6425d63d8014caaf21d14f6c13f989.jpgdfecb6f333f3955259dcda5d6ad40ed8.jpg

 

Edited by Simonon

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Lovely.  Wish I hadn't sold mine a few months ago!  I'm off to eBay to buy another....

 

(it needs to have the sticker like yours though)!

Edited by seaninbrisbane

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Guest Simonon
2 minutes ago, Honreekea said:

i need to do mine,  where did you get the belt kit from?

Just do a search on Ebay their is only one kit available. The belt/ idler kit is very good and the unit runs very quiet afterwards. Just photograph the pcb as mine lost a few wires when I removed the board. Pictures made it easy to find where they fell off.

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Guest Simonon
On ‎14‎/‎10‎/‎2018 at 7:50 PM, seaninbrisbane said:

Lovely.  Wish I hadn't sold mine a few months ago!  I'm off to eBay to buy another....

 

(it needs to have the sticker like yours though)!

Few things I have learned about these Sony WMD6C  units if buying especially off Ebay

  • Many are overpriced as everybody follows the guy listing one at silly money. Many have been on Ebay for over 6 months or more.
  • Many are Sony WMD-6 models which are Dolby B only, have a very early PCB with hard to get parts especially the capstan servo hybrid IC. If you look at the front and it says Dolby B only it is the first model. It does have the amorphorous head which is the better head though but I would avoid this model.
  • The Sony WMD-6C has Dolby C and an updated printed circuit board. Parts are readily available including the obsolete Sony CX20084 capstan servo chips with copies available on Ebay working fine. The latest units had a completely redesigned PCB featuring a simpler layout and surface mount components however it does not have the better amorphorous head which is printed on a label next to the volume control if it is the older revision.
  • Belts and idler kits are available on Ebay with the units running much quieter after these have been replaced. My unit resonated through the alloy case due to a hardened rubber capstan ring.
  • Non working units have usually been subjected to reverse polarity due to an incorrect DC plug pack. This results in a blown transistor in the DC converter and failure of the capstan servo IC which is a fiddly job requiring good solder skills. Factor repairs into your purchase price if buying a faulty unit. I would not touch the older WMD6 model if it is sold as not working for this reason. Some faulty units may have been worked on by a dodgy repairer with man made faults, be aware if purchasing from overseas.
  • Units purchased from tropical locations may be badly corroded due to sitting around in damp environments.....avoid these units
  • Be very  careful that the DC plugpack used is the correct polarity and check battery compartments for corrosion.
  • If working on these units be aware that circuit board wires break off easily. Photograph the printed circuit board and your progress frequently. I had a wire break off and located it easily due to taking quality pictures.
  • Take your time looking as they come up often. The Walkman central website is your friend when researching walkmans at http://www.walkmancentral.com/

Hope this information is helpful to future purchasers due to a renewed interest in these units.

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36 minutes ago, Simonon said:

Few things I have learned about these Sony WMD6C  units if buying especially off Ebay

  • Many are overpriced as everybody follows the guy listing one at silly money. Many have been on Ebay for over 6 months or more.
  • Many are Sony WMD-6 models which are Dolby B only, have a very early PCB with hard to get parts especially the capstan servo hybrid IC. If you look at the front and it says Dolby B only it is the first model. It does have the amorphorous head which is the better head though but I would avoid this model.
  • The Sony WMD-6C has Dolby C and an updated printed circuit board. Parts are readily available including the obsolete Sony CX20084 capstan servo chips with copies available on Ebay working fine. The latest units had a completely redesigned PCB featuring a simpler layout and surface mount components however it does not have the better amorphorous head which is printed on a label next to the volume control if it is the older revision.
  • Belts and idler kits are available on Ebay with the units running much quieter after these have been replaced. My unit resonated through the alloy case due to a hardened rubber capstan ring.
  • Non working units have usually been subjected to reverse polarity due to an incorrect DC plug pack. This results in a blown transistor in the DC converter and failure of the capstan servo IC which is a fiddly job requiring good solder skills. Factor repairs into your purchase price if buying a faulty unit. I would not touch the older WMD6 model if it is sold as not working for this reason. Some faulty units may have been worked on by a dodgy repairer with man made faults, be aware if purchasing from overseas.
  • Units purchased from tropical locations may be badly corroded due to sitting around in damp environments.....avoid these units
  • Be very  careful that the DC plugpack used is the correct polarity and check battery compartments for corrosion.
  • If working on these units be aware that circuit board wires break off easily. Photograph the printed circuit board and your progress frequently. I had a wire break off and located it easily due to taking quality pictures.
  • Take your time looking as they come up often. The Walkman central website is your friend when researching walkmans at http://www.walkmancentral.com/

Hope this information is helpful to future purchasers due to a renewed interest in these units.

Thanks for all that useful information....I'll take some time to read over it. I've jumped the gun and bought this:https://www.ebay.com.au/itm/SONY-PROFESSIONAL-WM-D6C-CASSETTE-RECORDER-One-owner-w-OPERATING-SERVICE-MANU/292771707088?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

 

Hope it turns out to be okay!  Best wishes, Sean

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Guest Simonon
Looks like it is a 'C' model - I hadn't even considered various iterations.
Looks like a good unit for a sensible price and its the C model.
If purchased in the late 80s it will most likely have the amorphorous head. I'm not sure of the revision date when they fitted the cheaper head.

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31 minutes ago, Simonon said:

Looks like a good unit for a sensible price and its the C model.
If purchased in the late 80s it will most likely have the amorphorous head. I'm not sure of the revision date when they fitted the cheaper head.

So some of the C models have the amorphous head?

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Guest Simonon
So some of the C models have the amorphous head?
If you read about them on walkman central the final revision had a radical departure from through hole components to a full surface mount component printed circuit board which is much cheaper to manufacture, neater and more reliable. Part way through this final revision they dropped the amorphorous head for a cheaper to manufacture type which wears quicker. I have not researched the serial numbers of when this was done. Unfortunately the final revision looks identical to the earlier WmD6C from the outside.
The serial nunber is inside the battery compartment. Removing the rear case will tell you your version straight away with good pictures on Walkman central.
They sound identical.

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Here is some info from tapeheads which is very helpful.
The original Hyperbolic Laser Amorphous, low serial numbers only of WMD6C and all of the WMD6. The label says: PA-259-3602A. Typical Serial Number of an early unit 10976. It also has a screw on its side to adjust inductance, I believe. After many hours of use, no head wear at all! It was only added to early D6Cs with the phenolic board. Low serial numbers only!

The most common standard Amorphous head. It's labelled 35711. Serial number of my unit is 169471. No head wear after many hours of use. Fitted to most machines with the SMD board, 2nd/3rd revision.

Finally the downgraded permalloy head. I need to check my records, but this head is marked 35712 if I remember correctly. It looks similar to the old head but this unit is missing the "Amorphous Head" marking on the front of the unit. The part no. in the service manual is different as well. Serial number of this unit is 531XXX. Quite a large amount of head wear after many hours, enough to throw the channels out of balance! 4th revision SMD board units, high serial numbers.

c2ee2ccc34d51f959235d6da025f4e9b.jpg2ad3e6f2211eeed36b9f038a1f934c92.jpg

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Guest Simonon

Besides the serial number here is the label near the volume control stating the amorphorous head.
Not present in late units with the permalloy head.
I guess we are now all well versed about Sony WMD6C pro walkmans70b6eb4a368f369155f13f1407d35e74.jpg

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I'm seriously impressed by your knowledge!  I've asked the seller for the serial number as it still hasn't been marked as 'shipped'.  Thanks.

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Well, it finally arrived and works well.  I also managed to source an original PSU, which should be arriving soon.  The serial number is 158240, with a 35711 head.

Edited by seaninbrisbane

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I would be very grateful if you could message me as I have one of these needing repair and would be happy to compensate you for your travails.

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