Sony DD series step-by-step repair guide for beginners

IT IS LUST ATTEMPT TO COPY-PASTE PART OF MY GUIDE TO NEW THREAD HERE.
IT IS UGLY AND NOT FINISHED DUE TO 40 IMAGE LIMIT.


Sony DD series (direct drive) walkmans are very popular among all cassette players because of their high quality construction, excellent audio sound quality, fully analog sound and because they’re different than other walkmans.

Although they’re well built, they will not work within specs without proper service. Because they’re 30+ years old, it is obvious that they have some common issues.



In this manual I will give very detailed step-by-step instructions how to fix all common problems and also what tasks to do so that future problems were prevented. With help of this manual, you should be able to do proper service of any DD unit. I’ve fixed more than 200 DD units. I will present my know-how and best practices that I discovered during my work with them. I will try to make it as complete as possible.


This manual is suitable for everyone with at least basic technical skills. Experienced technicians will also find many useful information here.


What skills do you need?

You need to have at least basic soldering skills
You should know how to work with screwdriver
You need to be patient and never use strong force to open or dismantle anything


What tools do you need?

Just simple and easily available tools. I will describe them later.


What models are covered?

WM-DD
WM-DDII
WM-DDIII
WM-DC2
WM-DD30
WM-DD33
WM-DD100
WM-F5
WM-D3

Workbench
Key to success is to prepare table where you will work.

- It must be clean – if you loose some small part, you will find it easier
- All tools and devices must be well organized – they should be at hand


Tools needed

Mandatory tools:

All needed tools are easily available for very low price. You can buy them on eBsy or Aliexpress if you already do not have them

- precision tweezers

- screwdriver: Philips type, PH00. Use high quality one, otherwise you will destroy screws. I use Vessel – this one will sure survive ages

- oil: synthetic oil for precision mechanics. Use the one that dries very slowly, like high-grade watch oil, 702 for example

- vaseline: there are special types for plastic and for metal

- pocket knife: the thinner, the better

- IPA: for cleaning

- cotton wool: for cleaning

- soldering station and accessories, or simple soldering iron

- external source: you can use 2*1.5V AA battery pack, instead. Use right connector and right polarity

- organizer

- 2.0mm Carbide End Mill Engraving Bits

- lamp with magnifying glass

Optional tools, according to situation
- scissors

- textile duct tape

- double-sided duct tape

- drills

- pliers

- small hammer, etc, as needed





Getting inside walkman
1. Remove the front door
Unscrew two screws located on both sides to remove the front door. Be careful not to break the hinges, they’re very fragile. If they’re already broken, you van fix them. Proceed to chapter “Fixing broken hinge”. If the door transparent plastic window is loose, proceed to chapter “Fixing loosened window”. If door lock slider is broken, proceed to chapter “Fixing broken door lock”.

Put the screws to safe place – organizer.



2. Tighten five screws located in cassette compartment
Many times they’re loosened. Sometimes they’re missing. These are standard M1.4 screws, easily available from eBay.



3. Remove the back cover
Unscrew 4 screws, two located on the bottom side and two located on the upper side.

Then pull out the back cover. Start from the empty side. Be very careful, there is spring located under door lock slider. Do not lose this spring! Hold the slider with your finger while releasing the back cover. Otherwise the slider will jump out, together with this small spring.

If you have troubles to remove the back cover, push both FF and REW buttons simultaneously, while trying to open it. Never use strong force to open anything.



WM-D3, WM-F5: tbd

4. Remove the printed circuit board
To remove PCB, you need to unscrew several screws and unsolder head wires.

Position of screws and head wire is marked on the images below. I made photos for WM-DC2, WM-DD100 and WM-DD. Procedure is almost the same for any model.

Before you start with removal, mark position and solder point of each wire. Otherwise it is possible that after manipulation, some wires will be released and you will not know where they belong to. These are usually wires coming from battery (Orange, Black), Motor (Black, Red or White, Red), two wires from FG coil (Black) and wires coming from switch (Blue, Violet) and Gray wire coming from head, with two or three wires inside (White -L, Red-R and optionally yellow) . You can also take photo but I prefer simple drawing.

Here is the removal procedure:

1. Remove black sticky tape holding gray head wire

2. Unsolder head wires from PCB (marked blue on the images). They’re marked on PCB either by color (letters R W Y) or by channel (letters L R C) or they’re not marked ans you have to draw their position in advance. Also, unsolder the ground wire and mark it’s location

3. Disconnect orange and black wires from battery holder. Either unsolder them from PCB or disconnect them from battery holder – push down the flat sheet with orange wire and pull out the spring minus pole with the black wire.

If possible, try to leave the black sticky tape, holding all wires together, where it is. It secures all wires and minimizes risk that the wires will be accidentally disconnected from the PCB

Another option is to remove the black tape and leave the orange and black wires connected on both sides. But I do not recommend this because sooner or later, one of these wires will break from PCB or from holder.

4. Unscrew all screws (marked red on the images)

5. Flip the PCB

WM-DC2





WM-DD100





WM-DD





WM-D3, WM-F5
tbd

Get access to broken center gear
In order to remove center gear from mechanics, several other parts need to be removed, first. In this guide, detailed removal instruction of these parts will be described.

Buttons removal

​

To remove buttons, they must be pulled out. Ensure, that walkman is in stop position. Catch firmly each of the buttons with your finger and pull it out. You can use little force to do it.


Only STOP button requires more attention. From cassette compartment side, locate hole into which this button is inserted. Push the black plastic something with tweezers while pulling the STOP button out.



Slider removal
Pastic slider is used to move head block up and down. This part is displayed on the following image.



To take it out, you have to remove:

1. the small spring

Use precision tweezers to remove it.

Warning: it uses to shoot out while you remove or install it.

Tip: Always hold another hand above it while trying to remove it. If it shoots out, you will at least know where to search for it

2. the washer

Use pocket knife to remove it.

Warning: it uses to shoot out while you remove or install it.

Tip: Always hold another hand above it while trying to remove it. If it shoots out, you will at least know where to search for it

3. the slider itself

Push it from the side of cassette compartment. Never try to remove it from the mechanics side. Otherwise you will break it.





Capstan wheel removal
First, unscrew two screws to remove the capstan wheel cover.



Second, remove the capstan wheel.

Warning: there is tiny plastic ring inserted on the capstan axle. It is barely visible and very easy to loose if you do not notice that it is there. It can be either black or transparent. Especially those transparent ones are almost invisible. The rings are very important to keep wow/flutter low. It can either stay inside cavity of the capstan wheel (OK) or can stay on FG coil:



In this case insert it back on capstan, push it inside the cavity of capstan wheel.

FG coil removal
Remove the FG coil displayed on the above image. Flip walkman, mechanics down, and unscrew three screws located from cassette compartment side.



Motor removal
Simply unscrew two screws that hold it. Push screwdriver firmly while trying to release them.



Take-up gear assembly removal
1. Remove large plastic gear by unscrewing one screw that is located in the middle of it



2. Remove small gear that is located under the large gear

3. Remove the spring



Center gear removal
To remove center gear from the mechanics, you have to remove two washers that hold it. Be careful not to loose these parts while removing them. Hold second hand above the gear, to avoid “shooting” washer to unknown space. There is spring located under the gear arm. Take it out.






Now disassemble the gear itself



Warning: there is tiny transparent plastic ring inside. Do not loose it.



Center gear repair
Clean old gear arm and metal disc


Install new gear
Screw six screws just like when you install wheel in your car. First one, then opposite one, etc. First, tighten them just very slightly, then stronger, etc.





Complete new gear
Put it all together




Secure screws with screw-locker.

Assembly & Maintenance
Whole assembly process should be done in reverse order. However, during assembly, lot of maintenance tasks should be performed

Clean mechanics
I use tweezers with cotton wool soaked in IPA alcohol. Clean every part of mechanics, especially those parts that contain remains of old oil or grease. Remember, old oil or grease acts as glue. Walkman will not run smoothly if you don’t clean it perfectly.

Clean the switch
Remove oxides from switch contacts. I prefer mechanical cleanup but you can use some deoxit available in your country. They’re usually available in spray version.



Clean battery contacts
Cleaning depends on condition of the battery contacts. When contacts are in good condition, it is enough to clean them with IPA. Heavily corroded contacts must be removed, first. Then you can clean them mechanically. Pull out minus (spring) battery contacts and push down plus (flat) battery contacts to remove them.

Warning: if you need to solder wire back to contact, remove it from plastic chassis, first. Othewise hot solder will melt and destroy plastic chassis.



Clean the potentiometer
Dirty or oxidized pot can cause serious troubles. From scratchy sound to intermittent control or even missing one or both channels. In most cases, it is only necessary to clean it. Sometimes, nothing helps and bad pot must be replaced.

I use special spray for potentiometers. After spraying of very little amount of liquid I turn with volume control several times, to remove all oxides and sulphides.



Apply oil and grease

​

Preventive tasks
Typical problem no.2 of DD walkmans is crack of another gear.

 

Thanks for publishing Marian, very detailed and helpful!


One question though: could you tell me where you buy your favourite anti-stress tools?
I think it's the most important part of the instruction

 

Marian you are simply working on a higher plane to most of us!

 

Wow Marian, you should be nominated for the Nobel Prize in Walkman!
One of my favorite photo is the one that shows the antistress tools – so cool.
It would be almost worth to open a special thread for appropriate antistress tools.

 

Brilliant....Can you do one for Sony WA 8800

 

Yes, antistress tools are the most important, of all. Especially chocolate. I don't know why I need to eat at least one per day

This manual is very ugly now, and the most important maintenance parts are missing there. On weekend, I will be able to continue on this manual.

 

Marian you have done an amazing job by creating this step by step guide.
Thank you for your time

Moderators please pin this topic which can help members for ever

 

Well done Marian, exceptional job

Glad the DD100 came in handy ;-)

 

This thread needs to be a sticky so no one misses it.

 

Mine arrived today.

The photos do the final product no justice. It's so finely made and perfect. The gear it's self is a real technical feat, and the quality of the build is fantastic. The components such as the ring and screws are amazing.

I have nothing to install it into at present as as the DD's I have to hand have all been repaired by Marian previously, and he has all my remaining broken gear units with him, waiting in the queue. So the hunt is on this weekend for a worthy DD broken gear candidate to fix with the new kit.

 

Great guide.
I can only add my 2 cents.
The plastic lever used to move the head block can be hard to remove and it could easily break if you apply too much force. The I found a way to easily remove it.
First remove the spring and plastic washer that holds it, then OPEN THE CASSETTE DOOR (like if you waned to insert the cassette) so the head is in a open position. Pull the lever up a bit so that is above the metal axle and rotate it towards the central gear for about 30 degrees. Viola.

 

Job well done Marian !!!!!

 

my 2 cents, it is better to have each thread set as sticky in its related forum; if there are too many sticky threads in the tech section, you could create a subforum "repair guide", but those thread should just be clean guides with no comments or reply. Discussion on the sticky guides should be done in dedicated threads to keep the guides clean.

 

+1

 

Simply awesome Marian. I think you've just lifted the value the DD's repaired with your new gear.

 

Hi, why is there a "blank page" at the end of the guide? Is there something no showing?
Thanks

 

Newbie here, is this the same gear as in the WM-F2?

 

welcome here,yes is the same gear.