I’m a big fan of Sennheiser earbuds. They might be somewhat pricier than other brands, but they do offer a premium experience. I love their sound, great fit, and numerous premium features like active/adaptive noise canceling, adjustable EQ settings, customizable controls, app support, water resistance, wireless charging, and impressive playtime.
Unfortunately, no earbuds are perfect. About a year after I bought my Sennheiser Momentum True Wireless 2 earbuds, one of my earbuds just stopped working. At first, I thought it was dead, but I spent a few hours researching and finally figured out how to fix my Sennheiser earbud.
To save you time and make the whole troubleshooting process easier, I have compiled a list of fixes that worked for various users. Read on to figure out why one of your Sennheiser earbuds is not working and find the fix that might work for your buds.
- Always start with the most basic things – keep your earbuds within the Bluetooth range of your phone and check if the faulty earbud has enough charge. If the earbud’s battery is empty, charge it.
- If the earbud won’t charge, make sure the charging contacts (on the earbud) and pins (inside the case) are touching each other. If the contacts are corroded or dirty, you should clean them. Also, if the magnets holding the earbuds in place become weak, even the slightest move could cause them to stop charging. Finally, if the earbud battery is dead or if your case is damaged, you may have to take the earbuds to the nearest service center.
- If the earbud is fully charged and turned on but won’t play any sound, you are either dealing with some firmware glitch or a dead earbud. To eliminate firmware glitches, try the following solutions: restart your connection (unpair the earbuds, forget them from your phone and pair them again), reconnect two earbuds together, update the earbuds, or reset the earbuds to factory settings.
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Fixing Sennheiser Earbuds One Side Not Working
Stay Within Bluetooth Range
I know it’s too obvious, but we have to cover the basics. Sennheiser earbuds have an impressive Bluetooth range, but like all Bluetooth devices, their range is limited. To ensure the best possible performance and reliable connection, stay within the traditional Bluetooth range of 33ft.
The Earbuds Might Malfunction When Used in Extreme Conditions
The recommended operating temperatures for the earbuds are from 0 °C to 40 °C (32 °F to 104 °F). If the temperature is significantly higher or lower than recommended, your earbuds, one or both, might malfunction.
I had this issue with my iPhone. It was really cold outside (about 0 °F), and my phone’s battery was at 50% at one moment, but it went flat a few seconds later. When I brought the phone back home, I gave it time to adjust to the room temperature. Then, I connected it to a charger, and the battery started charging again. The battery wasn’t completely dead, but cold weather caused it to lose its charge in just a few seconds.
Check if the Faulty Earbud Is Charged
This is another unlikely cause, but it is possible that your earbud is not charged or the battery is low. Maybe you left them inside the case for a few weeks. They were fully charged when you left them, but that doesn’t mean they are fully charged now. Earbuds lose charge at different paces, so it’s also possible that one earbud has some charge left while the other earbud is fully discharged.
If the earbud has little charge left, you should see it blinking red quickly three times when you try to turn it on. If there’s no charge at all, you won’t be able to turn it on.
The solution to this problem is quite simple – put the earbuds back in the case and charge them until the LED on the case turns green. If the case was also discharged, connect it to the charger as well.
If the case hasn’t been charged for quite some time, you may not even get an indication of charging at first. Do not disconnect the case, and don’t take the earbuds out. Leave them charging overnight and see what happens.
Earbud Not Charging – Check the Charging Contacts
While trying to charge your earbuds, you may discover that only one of your earbuds is charging, while the other is not. Since most Sennheiser earbuds don’t have LEDs on top of the control surface, it will be difficult to tell whether the earbuds are charging.
When the earbuds are inside the case and are charging, the LED on the case should be pulsing yellow. But this light might pulse yellow even if only one earbud is charging, and it will turn green when the earbud (and the case) is fully charged.
So, how do you tell whether the faulty Sennheiser earbud is charging or not? For starters, if a charging or battery error occurs, the light on the case should flash red three times.
But if the case doesn’t register one of the earbuds, it will not flash. Just leave the earbuds charging until the light on the case turns green, and take both earbuds out.
If one of the earbuds has a low charge, when you take it out and look at the earbud’s LED, it will flash red three times. In this case, it’s safe to assume the earbud has problems charging. It could be a battery malfunction, but it could also be a different kind of problem.
If the earbud doesn’t have any charge left, it won’t even turn on, and you won’t see the LED flashing red three times. Again, we can assume the battery is dead, but it could also be a different kind of charging issue.
So, let’s rule out other charging issues first.
The most common culprits of charging issues are corroded/dirty charging contacts/pins, or the lack of firm connection between the earbud charging contacts and the pins inside the case.
Start by cleaning the case and earbuds with special attention to charging contacts.
If they are just dirty, use a lint-free cloth, a cotton swab, and some isopropyl alcohol. If you can’t remove some stains, try using a toothbrush. A toothbrush can also come in handy when trying to remove corrosion.
Finally, if there’s visible corrosion on the contacts, you could use a high-grit sandpaper to gently remove this thin layer of corrosion.
When you are done cleaning the charging contacts and pins, try charging your faulty earbud and see what happens.
If the earbud is still not charging, you may want to check whether the connection between the contacts on the earbuds and the pins inside the case is firm enough.
If the magnets holding the earbuds become weak, the connection between the charging contacts and pins may not be firm enough to initiate charging. Try wiggling the earbud inside the charging slot or pressing it down to make sure the weak magnets are not causing this charging issue.
Furthermore, check whether the ear tips and fins are interfering with the case, preventing the charging contacts and pins from creating a firm connection.
Restart the Earbuds
Turning the earbuds off and then on could help when one of your earbuds is not working. Put the earbuds back in the case and close it. The earbuds will turn off automatically. Leave them inside for about 30 seconds. Then, open the case and take the earbuds out. Both earbuds should turn on automatically and go to pairing mode.
The second option is turning the earbuds off via the Smart Control app. However, this option is not supported by every Sennheiser earbud model. For example, the Sennheiser Momentum True Wireless 2 earbuds support this option, while the Sennheiser True Wireless 3 buds don’t support it.
If your earbuds don’t support this function, you could try enabling the Auto Power Off feature and setting it to 15 minutes. After you set the Auto Power Off function, take the earbuds out and let them connect to your phone, but don’t play anything. After 15 minutes of inactivity, the earbuds should turn off.
Unpair and Pair the Earbuds
Starting the connection between earbuds and your phone afresh could fix some bugs developed over time.
You just need to remove/forget your Sennheiser earbuds from the list of paired devices and pair them again. You could also try deleting the list of paired devices from the Smart Control app.
Pairing Sennheiser Earbuds – Step-by-Step Instructions
Pair Earbuds with Each Other (Sync Them)
Sennheiser offers instructions on how to pair two earbuds together when replacing a faulty earbud with a spare one. I believe this could also help when one of your earbuds is not working.
When one of the earbuds experiences some kind of firmware glitch (but it’s not completely dead), you could try pairing two earbuds together. It’s not a complicated process and takes just 20-30 seconds.
Syncing Sennheiser Momentum True Wireless 2
Disable Bluetooth on all devices previously paired with your earbuds.
Connect the case to the power source and put both earbuds inside the case. Don’t close the lid.
After 10-20 seconds, take both earbuds out and keep them close to each other. They should be blinking red.
Press and hold the touch-sensitive controls on both earbuds for 10 seconds. LEDs on both earbuds should be blinking green and red, and you should hear a voice prompt Pairing. Soon after, you should hear another voice prompt saying Pairing Successful and the LEDs should blink blue three times.
Syncing Sennheiser Momentum True Wireless 3
To sync two Sennheiser Momentum TW3 earbuds together, do the following:
Put both earbuds back in the case. DO NOT close the lid.
Wait for about 20 seconds. The LED on the case will blink red and green three times. This indicates the earbuds are synced together. Take them out.
Syncing Sennheiser Sport True Wireless Earbuds
Disable Bluetooth on your phone and other nearby devices. Make sure your earbuds are not connected to any device.
Put the earbuds back in the case. Connect the case to the power source. Make sure the earbuds are charged.
Open the lid, and take the right earbud out. It should be blinking red. Press and hold the control button for 10 seconds. The LED on the earbud will blink green and red, and you will hear a voice prompt Pairing.
Then, take the left earbud out and repeat the same procedure – press and hold the button for 10 seconds (until the LED starts blinking green and red).
Observe the LEDs on both earbuds. They should blink blue three times. You should also hear a voice prompt Pairing Successful.
Update Earbuds’ Firmware
A firmware glitch can also be fixed by updating your earbuds’ firmware. The only way to do this is through the Sennheiser Smart Control app.
Download the app, install it, and connect your earbuds to the app.
Assuming that your earbuds are connected to the app, there’ll be a message at the top of the screen informing you there’s a new update available. Alternatively, go to Settings, and you should see your firmware version at the top of the page (along with a potential Firmware Update message).
How to Update Sennheiser Earbuds – Video Tutorial
Reset the Earbuds
You can reset your Sennheiser earbuds in two ways – you can use the app or do it manually.
Resetting Sennheiser Earbuds Using the Smart Control App
This reset procedure is the same for every Sennheiser earbud model.
You need to download and install the app, and register your earbuds (connect them to the app). Once you are done, go to Settings – Factory Reset.
Resetting Sennheiser Momentum True Wireless 2 Manually
Connect the case to the power source. Put the earbuds inside. DO NOT close the lid. Press the touch controls on both buds for 12 seconds.
Resetting Sennheiser Momentum True Wireless 3 Manually
Disable Bluetooth on all nearby devices. You may also want to forget your earbuds from the Paired Devices list.
Put both earbuds in the charging case. Wait for a few seconds, and then take one. The manual suggests that you take the right earbud.
Press the button on the earbud for 10 seconds. The earbud LED should flash red and green. Release the button, and put the earbud back in the case. DO NOT close the lid – keep the case open.
In about 20 seconds, the earbuds will reset and pair with each other. The LED on the charging case will blink red and green three times.
How to Pair, Reset, and Update Firmware on Momentum 3 Earbuds
Resetting CX 400BT True Wireless Earbuds
To reset CX 400BT, you need to connect the case to the power source. Then, put both earbuds inside the case and make sure they are charging. DO NOT close the lid.
Press the buttons on both earbuds for 5 seconds.
Sennheiser Sport and Sennheiser CX True Wireless Earbuds
For these two earbud models, the same procedure used to sync two earbuds together is also used to reset the earbuds. So, scroll up and check out the instructions on how to sync two Sennheiser Sport earbuds together.
One Earbud Significantly Louder than the Other – Clean the Earbuds and Check Audio Balance
If one earbud is significantly louder than the other bud, your earbud driver might be clogged.
Remove the ear tips and wash them. Use anything you find suitable to clean the hole where the sound comes from (toothpick, toothbrush, paperclip, etc.). Remove as much dirt as possible, and see if the earbud is working.
How to Clean True Wireless Earbuds – Detailed Instructions
If one earbud is still louder than the other, you may want to check the Audio Balance settings on your phone.
On iPhones, the Audio Balance feature is found under Audio/Visual settings (Settings – Accessibility – Audio/Visual).
On Android devices, the Audio Balance feature is called Connected Audio and it’s found under Hearing Enhancement settings (Settings – Accessibility – Hearing Enhancements).
What If the Earbud Is Dead?
There aren’t many parts inside the earbud – you have the earbud driver, PCB (Printed Circuit Board), and battery.
If any of these tiny parts get damaged, the earbud will not work. Depending on which part is dead/damaged, the signs will be different. Below, you have the most common manifestations of driver failure, battery failure, and a dead PCB.
Dead driver – the LEDs indicate pairing, you can see when the earbud is paired, the earbud charges when you put it back in the case, but there is no sound coming out.
Dead battery – the earbud doesn’t turn on, there are no LEDs, and the earbud doesn’t charge.
Dead or faulty PCB – this one is the most confusing. The LED indicator could be all over the place, you may see different LED sequences or sounds coming from the earbud. Or the earbud might behave the same way as if the battery is dead.
Since all these parts are so tiny, fixing an earbud on your own requires serious skills and appropriate tools. It’s not a job for an inexperienced DIYer.
I would suggest contacting Sennheiser and asking for their help, especially if the earbuds are still under warranty. If the earbuds were not damaged by your actions (misuse, abuse, or malicious destruction), you might get a replacement.
Frequently Asked Questions
- Question: Why is only one of my Sennheiser earbuds working?
- Answer: Your Sennheiser earbud might stop working for a variety of reasons. Luckily, the most common reasons are firmware bugs and glitches that can be easily fixed by restarting the earbuds, forgetting the earbuds and pairing them afresh, re-syncing the earbuds, updating them, or resetting them.
- Other reasons for earbud malfunction include charging issues (corroded or dirty contacts), Bluetooth range issues, Bluetooth interference, extreme weather conditions (temperature and humidity), and wrong audio settings on your audio source.
- Finally, your Sennheiser earbud will not work if some part inside it is damaged or broken.
- Question: How do I reset my Sennheiser earbuds?
- Answer: Every Sennheiser earbud model can be reset via the Smart Control app. You just have to install the app, connect the earbuds, go to Settings, and select Factory Reset.
- Sennheiser earbuds can also be reset manually, but the procedure is not the same for every model. In this article, you can find detailed reset instructions for all Sennheiser true wireless earbuds.
- Question: How do you fix Sennheiser earbuds when one side is not charging?
- Answer: You could try cleaning the earbud’s charging contacts and pins inside the case. Furthermore, check whether the earbud contacts are touching the pins inside the case. The ear tips and fins might interfere with the case, preventing the earbud from charging. You should also check the magnets holding the earbuds in place. If they are too weak, the earbud will move inside the charging slot and, consequently, it will not charge.
- The earbud not charging could also be an indication of a dead earbud battery or damaged charging case.
- Question: Can my Sennheiser earbud be repaired?
- Answer: Theoretically, yes. In practice, the earbuds are so tiny and so difficult to take apart. It’s even harder to put everything back together. The hardest thing is replacing the damaged parts. It’s much easier to contact Sennheiser and ask them to repair your earbuds. Or you could just buy a spare earbud from Sennheiser.
- Question: Does dropping earbuds damage them?
- Answer: Dropping them once should not cause damage unless you are extremely unlucky. However, dropping them constantly will eventually cause damage.
I honestly can’t say I’m not happy with my Sennheiser earbuds. In fact, my Sennheiser Momentum TW2 are some of the most reliable earbuds I’ve ever had.
But when one of your Sennheiser earbuds is not working, you don’t care anymore about their great build quality, fantastic sound, or amazing features. You only want it fixed.
I hope this guide helped you troubleshoot your faulty Sennheiser earbud, locate the problem, and bring the earbud back to life.