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

Center gear repair

Clean the old gear arm and metal disc.

Install new gear

You can order a new gear on this page.

Screw in the six screws in the same sequence you install a wheel on your car: First one, then the 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

The whole assembly process should be done in reverse order. However, during assembly, a lot of maintenance tasks should be performed.

Clean mechanics

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

Clean head and pinch rollers

Clean pinch roller very carefully with cotton wool soaked in IPA, until it is like new.

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 the 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 (-) battery contacts (spring) and push down (+) battery contacts (flat metal) to remove them.

Warning: if you need to solder a wire back to the terminal, remove the terminal from the plastic chassis first. Othewise the heat and solder might melt and destroy the plastic chassis.

Clean the potentiometer

A 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’s only necessary to clean it. Sometimes nothing helps and a bad pot must be replaced.
I use a special cleaning-spray for potentiometers. After spraying a small amount of liquid I turn the volume control several times, to remove all oxides and sulphides.

Apply oil and grease

The whole assembly process should be done in reverse order:

  1. Install the center gear
  2. Install the FG coil – attach it using three screws from the cassette compartment side.
  3. Install the take-up reel assembly – spring, small gear and big gear. Hold the reel hub with your hand while fastening the screw.
  4. Install the plastic slider – move the head block down with your finger and push the slider back into the hole and align it correctly to the plastic lever!

Install the spring using tweezers, then install the washer.

It is very easy to lose them, be careful!

Apply grease to the slider, see below: