Marshall Major III / IV Headband and Earpad Replacement

Learning how to repair your own stuff is an invaluable skill, it keeps trash out of landfills, and it also asserts our right-to-repair (big sarcastic shoutout to companies who don't allow us to repair our stuff).

The nice thing about having a very technical hobby like FPV or something similar is that the better you get at building your drones or repairing your drones the more fearless you become at fixing other stuff like these pair of Martial Major III headphones that I got for my wife for Christmas 2019 I think so it has signs of wear and tear. The PU leather of the headbands and the ear pads really need replacing. Normally you'd have to bring it in to a 3rd party repair shop (Marshall themselves doesn't replace these), but it turns out all the skills I gained from building drones were more than enough for this surprisingly simple replacement! The bad thing about these headphones is that you have to desolder the wires just to get all of these old stuff out and I was trying to look for a tutorial on YouTube on how to do that. There were a couple of videos but they weren't really that much helpful or weren't that much clearer. It's not too technical or difficult, but I think I think this is going to be a useful Instructable for a lot of people who have these pair of headphones or similar Marshall headphones.

This guide is based on the Marshall Major III, but the process is entirely the same for the newer Marshall Major IV.

Supplies

You can buy the replacement parts here:

Earpads - Amazon | AliExpress | Lazada | Shopee

Headband - Amazon | AliExpress | Lazada | Shopee

TS100/101 Smart Soldering Iron - Makerfire | Amazon

Step 1: Skills Required

The only special skill required for this repair is soldering. If you don't know what soldering is, it's basically melting a small amount of conductive material (solder) to attaches wires to a circuit board or other electronic component. There's really nothing especially difficult about it, just dexterity especially with tiny wires and circuit board pads. And if you mess something up, you can desolder (detach) and resolder again.

The main thing I would recommend is to get a decent soldering iron. This will be an invaluable tool to add to your workbench, as you can do a lot of things with it. A decent soldering iron, as opposed to the cheap ones you can find in a hardware store, will also give you a more stable and controlled temperature as well as the option to change the tips for different applications e.g. wider tip for bigger jobs or a thinner pencil tip for delicate jobs.

For the soldering iron I used, I used the TS100, but it's already phased out in favor of it's newer brother the TS101. It's also not really that expensive, so I highly recommend it.

Step 2: Removing the Old Parts

First we need to remove the ear pads by turning it counterclockwise. Next we need to remove these copper pegs that holds the earpiece to the headband (you only need to remove the left ear). Next we need to unscrew the screws on the left side. I think we still need to remove most of the components from the inside like this control board. There are some screws holding the board in, so you just need to use a screwdriver to take them out.

You'll also need to remove the battery which is held on by some adhesive, so you'll need something like something plastic to pry it out (don't use anything sharp or metallic to avoid puncturing the battery). All of the wires are soldered onto the board, the battery, and is also connected to a smaller board which is connected to the button on the left. And you'll need to pop the plastic retainer up. There is a lock there but just gently pop it up and it should be fine.

Next we will need to desolder all of the wires from the board, but before that take note or take a photo so you know which wires go where when we put it back together.

Now pull the whole bunch of wires out. it's a little bit tight so you might have to get these wires out one by one. Finally we slide the old headband out and push it off from the other side.

Step 3: Inserting the New Headband

Now we take out our replacement headband and earpads. Our replacement headband has "left" and "right" indicated on the sides, so you know which side goes where. We'll need to wrap all the wire ends together with some tape so it's easier to move in through the headband. If you have a long cylindrical object like a small, thin paintbrush or hard straw then you'll need that to help guide the wires through the headband. Just tape the end of the wires to the paintbrush or whatever long, hard object you have and slide the whole thing inside and it's easier to push. Just keep pushing you reach the other side and then you can start pulling from the other side as well.

Step 4: Putting Back the Electronics and New Earpads

Once you get the headband through, the worst is over and we can just start putting this back together. First we need to push the wires through the hole again and you can twist them so that they go in easier. We'll need to take out our notes or photo we took earlier so we can solder the wires back to their original solder pads. Then we put the battery back in and screw the boards in and once that's done we can now just close this up and screw them shut.

Step 5: Attaching the New Earpads

Next we put the copper pegs back in to the holes. Finally we just screw our near earpads clockwise. So now we have this new-looking pair of Marshall Major headphones. All of the rubber/PU leather parts have been replaced, and it's also working; I turned it on and connected to my phone to check. All that's left to do is give this back to my wife! Now my wife has an "almost new" Marshall Major III headphones, or at least it looks like a new or refurbished unit, without having to spend a lot paying a repair shop!