Sony WH-1000XM4 Motherboard Replacement

Introduction

Follow this guide to replace the motherboard on the Sony WH-1000XM4 wireless headphones.

Ensure the headphones are powered off and discharged.

As a precaution utilize the antistatic wrist strap to avoid damaging any of the electronic components.

You will need solder to reassemble.

Before beginning any repairs, press and hold the power button on the left ear cup for about 2 seconds until the blue light turns off.
Place your headphones onto a work surface, ear pads facing up.

Use your thumb to depress the LEFT ear pad near the long outer edge, creating a gap between the cushion and the frame. (The right ear cup is pictured, but the process is identical for the left ear cup.)
Pivot the spudger down to unclip the long edge of the ear pad.
Repeat around the perimeter of the ear pad until it is loose.
When the first clip disconnects, you'll hear an audible clicking sound.
This may take a considerable amount of force. If the cushion won't click out of place, move your spudger to different points along the long edge.

Remove the left ear pad. (The right ear cup is pictured, but the process is identical for the left ear cup.)

Remove the foam liner from the left ear cup's speaker. (The right ear cup is pictured, but the process is identical for the left ear cup.)

Use a Phillips #00 screwdriver to remove the four 8.4 mm screws securing the left ear cup cover. (The right ear cup is pictured, but the process is identical for the left ear cup.)

Flip the headphones over, ear cups facing down.
Use your fingers to lift up and flip over the left ear cup cover.
Don't try to completely remove the cover just yet—it's still attached with many cables.

Unscrew the 4 screws in the corners of the motherboard to loosen it from the left ear cup assembly.

Carefully remove the multipin connector (multiple colorful wires) from the side of the motherboard.

Carefully lift the motherboard out from the ear cup to access the other cable ribbons and connectors.

Remove wires from the side or bottom of the motherboard that are attached by pin connectors.

Desolder the remaining wires that are attached to the motherboard.
Repeat steps in reverse order to reassemble the headphones after seating the new motherboard.
Reference the Service Manual on the Sony WH-1000XM4 main page on the iFixit website to verify correct wire connections.