iFixit - Answers With Device "Sennheiser Headphone"

Sennheiser RS120: Why doesn't my transmitter turn on?

Mon, 25 Nov 2024 21:36:27 -0700

The green transmit lite on my transmitter doesn't

come on anymore to indicate the unit is transmitting.

It isn't transmitting. All connections are ok.

Any advice??

Thanks,

Paul Hipp

paulhipp@aol.com

⟐ Answer edited November 25, 2024 at 21:36 MST

Sennheiser momentum 4: Why do I have static noise in my left earcup?

Tue, 20 Jan 2026 05:40:33 -0700

Since I got these headphones I fell in love with with the brilliant sound as well as comfort. But my left earcup started to make some static noise. It started a month ago when my headphones randomly turned off by them selfs.(they still do sometimes) Has anyone an idea what i could do to fix them?(Yes i tried uninstalling everything and setting them back but it didnt work)

⟐ Commented January 20, 2026 at 5:40 MST

Sennheiser RS120: Why do they keep cutting out?

Sat, 11 Jan 2025 20:05:53 -0700

I got these headphones and they worked great except for one thing. About every 30 minutes the sound cut out and was replaced with deafening feedback noises. I can fix it by unplugging and plugging back in but it keeps happening. Please help.

⟐ Commented January 11, 2025 at 20:05 MST

Sennheiser RS120: Frequently I get a very very loud static sound in my earphones

Sun, 01 Sep 2024 12:04:17 -0700

I have two headsets for the RS 120. One is fine. The other one sends a horrible loud burst of static every now and then and scares the !&&* out of me. Can anyone relate?

Can anyone advise how I could prevent this?

Thank you.

⟐ Answered September 01, 2024 at 12:04 MST

Sennheiser RS120: The green led light comes on and goes out often

Sat, 26 Aug 2023 20:29:12 -0700

When the green light is on and I use the headphones they last about 10 minutes and goes out and all I get is static.

⟐ Commented August 26, 2023 at 20:29 MST

Sennheiser RS120: We get the red light, but not the green light, and we get static

Thu, 25 Dec 2025 08:34:08 -0700

WE do not get green light and just static. Is there anyway I can fix this?

⟐ Commented December 25, 2025 at 8:34 MST

Sennheiser RS120: stopped working no sound no red light

Wed, 14 Feb 2024 23:50:24 -0700

ok - hello and how are all ?

New to this - so question

Sennheiser hdr 120 - had them about 5 years - recently replaced the batteries as thought that was the reason they were not holding the charge. But now new - already charged batteries, still no sound.

Cradle - unplugged, and same with headphones - removed batteries for the 15 min reset, plugged back in and batteries back in - still both no sound - despite tuning and volume up to wait - nothing. No red light on cradle.

I get green light on as soon as i switch plug on for power, just no red light when headphones on cradle.

Been like this for about a week - last time had to update the driver on my pc - and then it worked great until 3 days later, so could be coincidental or not. Just know its getting tedious now and the thought of replacing the whole lot is a tad of a minefield - as too much choice and prices are more now

so all or any help be good

much appreciated

⟐ Commented February 14, 2024 at 23:50 MST

Sennheiser Headphone: Sennheiser HD 450bt Malfunction?

Fri, 28 Nov 2025 15:19:14 -0700

My headphones seem to be malfunctioning or something? I didn’t get them long ago. I used them this morning and it was fine but when I went to turn them back on it is refusing to pair. Just says power on and flashes a couple times then remains blue. And then I cannot power it back off and none of the buttons seem to work and the refresh isn’t working. When plugged into the audio jack they work fine but unfortunately my phone doesn’t have one. Anybody that can help?

⟐ Commented November 28, 2025 at 15:19 MST

Sennheiser RS120: One headphone does not work

Wed, 07 Oct 2020 05:31:01 -0700

I only listen to the tv in mono with one headphone, not in stereo with both headphones. I already checked the electrical connection between both headphones. I changed also the battery, but still the same. Any idea what is wrong and how to fix it will be higly appreciated. Thanks

⟐ Answered October 07, 2020 at 5:31 MST

Sennheiser RS120: Charge LEd does not show

Tue, 08 Sep 2015 01:48:28 -0700

The sennheiser 120 when plugged in I get the green LED light on but the the red LED light does not come on.

⟐ Commented September 08, 2015 at 1:48 MST

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 HD428: Why is my headphones only working in one side

Tue, 18 Apr 2017 10:24:37 -0700

Why is my headphone only working in one side is it because theres a missing line on the plug or is there a technical problem?

⟐ Commented April 18, 2017 at 10:24 MST

Sennheiser pxc 550: ANC static when adjusting

Sat, 08 Mar 2025 14:56:25 -0700

So I get static in the left side. It sounds like the static you get when you drag your finger over the needle of a record player. It happens when ANC is on and;

1 I wiggle my ears to adjust them

2 turn the left earcup into the off position

3 adjust the headband fit but only the left side.

4 sometimes just always on

It seems like when the pressure in that side changes it happens. I have opened it up and did not see anything obviously wrong, like bad soldering or worn wires. It makes me think that there is an issue with a mic in the earcup. I also think this because I have used it with only the left ear on but the right behind my ear so I can hear around me with and without the ANC on.

When I opened it up there was the main driver and then four paper covered things around it. They all looked good to me I can upload photos if it would help.

⟐ Commented March 08, 2025 at 14:56 MST

Sennheiser RS120: Green light does not go on

Mon, 19 Dec 2016 15:15:37 -0700

unit worked for one year. Now green "on" light does not go on......just the red. No reception. Tried unplugging as mentioned in other q&A but that doesn't work. Feel that I have to return the thing for replacement.

Thanks!

Sennheiser HD428: How do I repair the volume control?

Fri, 08 Jul 2022 22:44:37 -0700

Sennheiser HD 4.40 BT

I really need some help. My dad just brought me a pair of Sennheiser HD 4.40 BT, and withing 3 days, I dropped them, and now the up on the volume control is mushy and doesn't do anything. The down volume still works. How would I fix it? And where could I get the parts? Thanks in advance.

⟐ Commented July 08, 2022 at 22:44 MST

sennheiser hd 4.50: broken female jack, how to fix

Fri, 18 Jul 2025 02:05:23 -0700

The female jack on my headphones are mostly broken. Most of the time there is no sound but if i move the cord to the right place there is quiet sound in either ear, or rarely normal sound in both ears. (if i hold it there) Is there any way I can fix the jack in these headphones so that it works properly? It is NOT the cord/male jack with the problem, I tried 3 different cords and they all have the same problem in these headphones and not elsewhere

(also if questions dont show device its a sennheiser hd 4.50)

⟐ Commented July 18, 2025 at 2:05 MST

Senheiser Momentum: One headphone sound went out

Sat, 16 Mar 2024 14:40:37 -0700

Attempting to fix instead of replace. Once headphone went out - opened it up and no obviously burnt or disconnected cables. It is the left side speaker, which is where the wire plugs in.

I can confirm both speakers are being powered because sound still works perfectly on the right side.

Any advice?

⟐ Answered March 16, 2024 at 14:40 MST

Sennheiser RS120: Right ear only works when volume dial is in juuuuust right place

Mon, 14 Nov 2022 04:54:09 -0700

The left ear sounds fine, so I'm confident it's not a tuning issue. But the right ear only works if the volume dial is in one VERY specific place. Which, of course means I have no control over the volume if I want to hear in both ears. If the volume dial is not in the right spot I just get static. Halp!

Any ideas?

⟐ Commented November 14, 2022 at 4:54 MST

Sennheiser pxc 550: PXC-550 II (!) won't charge, right earpiece heats up

Thu, 16 Nov 2023 23:48:08 -0700

Is there any information on charging controller, right earpiece board or photos of said things for PXC-550 II?

Story:

I have a pair of PXC-550 II (there's no page for the updated model, sorry). Due to my carelessness, I left them on for around 6 hours and they've completely drained the battery. I haven't done that with them yet. Then I tried to leave them on a charger for some while. When I returned, the sensor pad area was too warm, I can't really describe it as "hot", but it was like a laptop power brick in terms of temperature. There was no indication of charging. I removed them from the charger, and decided to disassemble them to find maybe the cause of heating up. After I've removed dynamic, I connected the power again to find what's heating up. It were, as far as I can tell, two ceramic capacitors. There were no visible heat damage or any kind of smell. That said, the indication appeared in form of red LED, with user's manual "less than 2% charge" that's deep discharge. Trying to push the battery out of that state generates more heat than during normal charging, but I couldn't tell if it wasn't too much heat. Although it did push out of that state, but 10 seconds after it stopped charging, either from protection kicking in, or, more likely, charging circuit breaking due to final failure of the charge controller. Still, there were no signs of burned electronics. I gave the headphones to a more knowledgeable and geared person in terms of board repair, but if you happen have some info on the right earpiece board (or just photos of both sides), it can help them (and me) greatly

Edit. I forgot to add, during all that time, the headset kept working on the "brains" level - it could turn on, connect to the devices, change the ANC modes, and sensor panel fully worked. But it soon always turned off due to low charge, even when connected with charger. I relatively know my problem, it's deeply dead battery that needs a "jump" (probably) and charging controller that's probably kicked the bucket. I need some sort of board images to locate and identify said charger so we can be sure that we can get the part and that painful board removal will bear fruit.

⟐ Answered November 16, 2023 at 23:48 MST

Sennheiser Headphone: Sennheiser Momentum 3 wireless headband/earpads

Fri, 21 Jul 2023 01:21:26 -0700

The headband plastic has split open at the bottom. It has also gotten sticky over time (I guess it's not real leather?) Even cleaning with soap or alcohol does not help.

The earpads have worn out and the vinyl layer is peeling off. It's also not very breathable.

Would like to replace both - has anyone found quality third-party parts for these?

End up looking into it again - Sennheiser does not provide parts for the headband.

This is clearly not the case since I can see it is removable with a few screws. Planned obsolescence for a high-end product.

It took me TWO minutes to remove the leather band.

Thanks for your request. Unfortunately the headband is not replaceable and not available individually.

⟐ Edited by author July 21, 2023 at 1:21 MST