iFixit - Answers With Device "Sennheiser HD350 BT"

Sennheiser HD350 BT: My headphones are not working

Fri, 09 May 2025 12:15:36 -0700

It is not turning on, it shows red light when I put it on charge but it's not turning on and not even showing any light when I plug it out from charge

⟐ Answered May 09, 2025 at 12:15 MST

Sennheiser HD350 BT: ON/OFF button not clicky anymore

Fri, 22 May 2026 12:02:01 -0700

My 4 year old Sennheiser headphones started acting weird a few months back. The on/off button is no longer feeling clicky and requires some extra effort to push.

Regardless of push time, in 9/10 cases the headphones enter pairing mode. In the 1/10 cases I pushed the button at just the right angle to avoid it.

Upon opening them, I realised that the actuating part of the button (the electronic bit) definitely is mot as clicky as the volume up one and experimenting with a thin screwdriver bit made me realise it's a game of chance with 2/10 presses entering pairing mode and 8/10 working just right. The deciding factor was pressure. There is no blockage or problem I can identify with the exterior plastic button.

Is there anything I can do to fix it? Part of me doesn't want to accept it but it seems the actuator is soldered and not replaceable without significant investment in equipment.

⟐ Commented May 22, 2026 at 12:02 MST

Sennheiser HD350 BT: Screw deeper than the others stops me from opening them

Sat, 11 Oct 2025 10:12:40 -0700

Hi!
Recently I started working on my headphones as they were stuck in a power off/pairing cycle and I believe the power button is the culprit. While opening them up, I realized my headphones were a bit different from the other guides - the screws weren't coming off entirely (3/4 are unscrewed to the point where turning them makes them "hop" in place) and one of them had a hole of a different size, so small that my screwdriver wouldn't fit.

Upon taking a closer look and digging out some of the plastic to make the hole larger, I realized it is very deep (about twice deeper than the others). Any recommendations on how to approach this?

⟐ Answer accepted October 11, 2025 at 10:12 MST