Bose QuietComfort 35, 35II and 45 Volume and Play/Pause Buttons Replacement

ID: 204851

Description: This guide will show you how to replace the...

Steps:

1. Ensure your headphones are off by moving the power switch to the off position.

2. Feel inside the right ear cushion (labelled 'R') for the hard ring that sits between the soft cushion and the mesh cloth.
3. Pinch that ring firmly from both sides and pull it inwards slightly until it unclips that section of the cushion
4. Work your way around the cushion doing the same thing until it comes loose, then remove it completely.

5. Gently peel up the mesh cloth on the top and bottom, without removing it completely.
6. Remove the 3 screws holding the back plate in place using a J000 screwdriver bit.

7. On the QC45, the back plate is only held in by the screws we just removed, but on the QC35 and 35II, it may also be held in by clips.
8. If the back plate doesn't come off easily, slide a thin flathead screwdriver bit (like the 2mm flathead bit) between the power switch and the back plate, and lever it off
9. Carefully fold open the back plate like a book, be careful because it will still be attached by a ribbon cable on one side, that you must not break.

10. Locate the small gap in the rim around where the buttons connect to the case and insert a small and thin flathead screwdriver bit (like the 2mm flathead bit) into it as deep as it goes.
11. Lever it out until the button cover piece starts to pop out.
12. Using a spudger or small flathead screwdriver, carefully work around the edge of the button cover until it can be removed. Be careful not to break the clips or the right-angled light pipe attached to the cover that drives the power/status LED.

13. Using a spudger or small flathead screwdriver, lift up the button flex PCB from the end that says "button flex" (not the end that says "BOSE"), until the PCB is loose.
14. Note that it will still be attached via a ribbon cable through a small slot into the back of the ear cup.

15. Locate the USB driver board at the bottom of the ear cup.
16. Remove the 2 screws holding it in place using a J000 screwdriver bit. Do not confuse these with the 3 screws remove earlier, as these are much shorter.
17. Using a spudger or small flathead screwdriver, gently lever the USB board up as far as it will easily go, just enough to see most of the USB port outside the housing. Be very careful not to damage the board, or the large orange ribbon cable.

18. Locate the small ribbon cable connecting the button flex PCB to the USB board. Be careful not to confuse this with the large ribbon cable that connects the USB board to the rest of the device.
19. Using tweezers, gently pull the ribbon cable out of the socket on the USB board, pulling in the same direction as the cable. Don't worry too much about damaging the cable, as this is part of the button flex PCB we are replacing.

20. Looking from the end with the button flex PCB, locate the tiny slot where the ribbon cable enters the main body of the ear cup and remember it's location for reassembly.
21. Gently pull the button flex PCB out of the device to remove it completely. Note that the ribbon cable has a 90° bend in it so you may have to rotate the PCB to get it out.

22. Take the new button flex PCB and ensure it is the correct way up, with the buttons facing outwards.
23. Slide the ribbon cable back through the slot that the old one was removed from, again being aware of the 90° bend in the cable, until the button flex PCB is back in position.
24. Align the two small holes on the button flex PCB with the two mounting spikes in the case, and push it into place.
25. You may find that the new PCB doesn't want to stay in place, in which case you can optionally add a tiny amount of hot glue to the mounting spikes after inserting the PCB, which will hold it in place. Hot glue is ideal because it can easily be removed if needed.

26. Using tweezers, gently align the ribbon cable from the new button flex PCB with the socket on the USB board. Be very careful not to pinch or bend the ribbon cable too much during this step.
27. Once lined up, slide the ribbon cable into the socket. It's a tight connector but shouldn't require too much force to attach.

28. Gently push the USB driver board back into the housing, being careful not to damage the board or the ribbon cables.
29. Check that the USB port is lined up with the hole for the USB cable, then re-insert the two short screws to hold the board in place.

30. If you didn't hot glue the button flex PCB in place, you will need to use a spudger or thin flathead screwdriver to hold the flex PCB in place. Make sure the mounting spikes are engaged in the holes on the flex PCB, then use your tool to hold it in place from the end labelled "button flex" whilst you attach the cover.
31. Orientate the button cover correctly, and align the light pipe for the status LED with the hole it slots into next to the flex PCB.
32. Starting at the end with the status LED gently press the button cover back into place until the clips engage.

33. Close the back plate on the ear cup, lining it up with the power switch and being careful not to damage the ribbon cable.
34. Hold it in place and turn over the ear cup, then re-insert the three screws to hold it in place.

35. Align the ear cushion with the ear cup.
36. Starting at either the top or bottom, slowly work your way around the ear cup and push the hard ring of the ear cushion back under each of the 10 clips.
37. This can sometimes been quite tricky, especially the last few clips. If you're having trouble, there are plenty of guides online on how to replace the ear cushions on these headphones, including how to re-attach them.