Sony MDR-SA3000 - Driver Repair !?
May 8, 2023 at 8:19 AM Thread Starter Post #1 of 1

GREQ

Headphoneus Supremus
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I recently purchased a faulty Sony MDR-SA3000 with hope/expectation that all it needed was a cable repair.
Instead the driver was completely dead, giving no ohm reading.

Not being one to give up, and with a little soldering experience under my belt, I did some research and actually found a post on a Chinese forum where someone actually managed to repair an MDR-SA5000 driver.
This told me everything I needed to know - it was possible.

Normally, I wouldn't go through this much effort for a driver, but these things are stupid rare, and I really wanted to hear this headphone!

_DSC8913.jpgFirst step is removing the magnet housing from the driver.

I used a scalpel to carefully destroy the glue around the circumference of the back part.
Then I slowly prized it out with a small flathead screwdriver, slowly working my way around in small increments.

I left the driver on the baffle for this step as it was easier to handle and safer with the knife.
_DSC8918.jpgThe diaphragm is much easier to remove.
From the FRONT, you can push it out using something soft like a guitar pick, which fits well through the edges of the front grill.

Again, work your way around slowly and incrementally. You don't want to bend the metal ring that the diaphragm is glued to.
_DSC8925.jpgThe next step is VERY difficult.
The voice wire is laminated together and held around the inside of the diaphragm edge with this strange green 'glue' which isn't set... it's kind of a dry rubbery jelly.

A small length needs to be pulled out of this glue.
It is EXTREMELY easy to break the voice wire while pulling it out.
The steadiest of hands is required for this.
Also, do not apply too much pressure with tweezers, as this will also cut the wire.

I know this because it happened twice!
Luckily, there is quite a generous 25mm or so of extra voice wire glued around the edge of the driver.
_DSC8927.jpgTo the naked eye, this looks like one wire.
1683545816344.png
I used a microscope and a fresh scalpel to carefully separate the laminated voice wires.
_DSC8964.jpgI can work with this... I think...
Then put the driver back together...
Be very careful not to push the diaphragm too deeply back into the housing - it seems like it is actually possible to push it too close to the grills.
I had very severe bass buzzing on my first repair.
I had to do a full disassembly and try again....
_DSC8965.jpgTest 1:
I soldered two single strands of speaker wire from the driver contacts leading to the edge where the voice wires come out.

Then I covered both sides with electronic silver paint - the kind you get for model railways etc.

This did not work.
_DSC8968.jpgTest 1 continued...
Drowned both connections in solder while they were still covered in silver paint with some twisted strands of speaker wire.

THIS WORKED
Then I broke it while trying to fix the bass buzzing...
_DSC8974.jpgTake 2...

This time I 'extended' the contact points with 2 strands of speaker wire.

This didn't work immediately, so I tried re-heating the wire... maybe there was more laminated coating on them?
That didn't seem to work either.

So, I added some silver paint on the joints and re-heated them with the iron.

Somehow this worked!?
_DSC8976.jpg
1683547506006.png
Just another angle of the same thing.




And a closeup... this stuff is thinner than human hair.

Fin
_DSC8961.jpg
Sony MDR-SA3000.jpg


Now the obvious question - is this a proper repair?
- no, of course not.

The driver does make sound, and listening to music with it sounds great... no buzzing or imbalance, etc.
But there are clearly some issues as these are not put back together wit the same tolerances that the original was made with.

Is it perfect? - no
Does it matter - that's up to you.... as for me, it's good enough!
 

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