Plantronics M165 bluetooth headset teardown - Making a hole for the microphone to fix the low volume and make the other person hear you better

Some month ago I decided I should get a Bluetooth headset for my smartphone, mainly to get less RF to my head :-)
After some research and reviews reading activity I opted for a Plantronics M165 Marque 2 (I bought it on Amazon, they always have a fantastic customer service).
It looked nice, with a practical "hear plugging" system, and the reviews were good.

Effectively the headset is very nice, very light, and fit perfectly in my hears.

BUT, there is an issue, a big one (in my opinion).
The sensitivity of the mike is too low, if there is a bit of noise around me, the person I'm talking to hear the noise instead of my voice.
So, this Plantronics M165 Mk2 works nicely when I'm in a silent room, but if I'm outside near a road it is totally useless, I need to turn it off and recall the person without the headset. This happened to me so many times that I've stopped using this headset.

Just to be clear about the level of noise I'm talking about: when I'm in the office, in the outskirts of the city, then I go on the balcony: we are on the 4th floor, and the nearest road is at about 60mt. Here, the noise of the road is enough that I can't use the headset.

I asked myself why I can't use the headset with such a low noise... maybe that my headset is broken/defective? it is possible...
But I think there is a better explanation: this headset DOESN'T have a hole for the microphone.

Take a look at the following image, a photo of the frontal part of the headset.
There isn't any hole, it's all solid plastic, and the microphone is behind this plastic.
How can it hear my voice?

There is second mike (for noise reduction) that instead it's near some hole facing "the noise" on the opposite side of my mouth.
Here you can see an image of the hole near the "noise reduction" mike.
I've circled them in red because they are so tiny that even with a macro photo you can barely see them. They are very tiny, about 2-3mm x 0,5mm and are "trapped" between the plastic bezel of the headset.

In my opinion, this can't work well.
Any headset I've ever seen have a hole for the mike, why the Plantronics M165 doesn't have it?

Now, I think I understood the problem: no hole for the mike.
I have also decided that this headset is useless for me, because it can work only in a silent room, which is not the the typical situation where I want to use it.

So maybe I can find a way to fix it? If only I knew where exactly the mike is, then I could make a hole for it.
So, why not try to dismantle it? :-)

I always loved to dismantle things, and I know that try to dismantle a headset can be a one-way street. Sometime they are glued together, and they are so tiny that it's really easy to break something.
Anyway, I should at least try :-)

So here is my venture in dismantling and fixing my headset.
To dismantle it I've used some plastic opening tool and some mini screwdriver.

Typical plastic opening tool

After trying to put the opening tool in any spot I could find, I've been able to open my way into the headset.
In the following image you can see the partly opened headset.
In red I've circled the only existing opening on the headset, them are near the "noise reduction" mike. Through these holes the headset can listen for the ambient noise.
Circled in yellow there is one of the 5 clips that hold the headset together.

  Here are some other images of the partly dismantled headset.
 

After some more pulling and bending I've been able to open the headset.

In the following images you can see the external part of the headset.
Circled in Green there are the 5 clips that keep the headset together.
Circled in Red and Orange there are other 2 clips that hold the headset together.
These last 2 clips are very hard to "unclip" because them are very tiny, and you cant use the typical plastic opening tool to unclip them (because them are placed in the corer of the headset)

As you can see from the photo, the Orange one is missing, I  broke it during the opening procedure... :-(

 

Now we can take a look inside the headset.
Circled in red there are the hooks of the clips.
Circled in green the leds of the headset.
Circled in pink the switch of the main button.
Circled in yellow is the bluetooth antenna.
Circled in blue is what I suppose to be the "noise reduction" mike.

And where is the microphone for the voice?
Let's take a closer look...

 Look at the object circled in red, it looks very similar the the noise reduction mike (circled in blu)

Let me check better.. I can also slip a piece of paper under it, it definitely seem to be the voice mike.

Now I know exactly where I need to make a hole, on the external plastic of the headset :-)
So, let's drill a hole in this deaf plastic shell!
To make the hole I've simply used my old trusty Olfa Cutter

 

And after some hand drilling... Ta-daaaa!
Here is my modded version of the Plantronics M165 Marque 2, now with a hole for the mike, so that the person you are calling can hear you better :-)

Here you can see the voice-microphone through the hole :-)

I reassembled the headset, and I'm happy to tell you that it stay together perfectly, even with a broken clip.

Clearly the headset have now some sign of the surgery procedure it went over :-)

 

 

Now the headset works way better than before, and I can talk on the balcony of the office without any issue! :-)
 

How to flash android factory image without wiping your device - Unbrick your rooted android after a failed OTA update from 4.3 to 4.4 kitkat

I own a Nexus 7 WiFi (2012) on Android 4.3, unlocked and rooted, stock rom.
Long story short: I received the OTA update to android 4.4, I executed the update... and it bricked my Nexus 7.
I've been able to restore my tablet without wiping it by installing the 4.4 factory image.

Installing a factory image will wipe your device, but it's possible to modify the installation script so that it wont delete userdata, nor wipe the device.

About the rooting
When I received the OTA update for 4.4 id didn't unroot before installing it, after all I updated from 4.1 to 4.2 and from 4.2 t 4.3 without unrooting... but this time it didn't work out.
So, keep a note for myself: always unroot before applying system update.
(anyway, this kind of error happened even to person with stock unrooted tablet... so I will never know if the error I got during the update was due to my tablet being rooted)

Fixing the reboot loop
When I got the error my tablet then got stuck in a reboot cycle.
Tablet start up, and then after some time show a "no comand" error, and then reboot, and continue like this...
In this situation I wasn't unable to turn off the tablet, and I didn't want it to drain all the battery.
Looking for a fast and effective way to turn it of, I decided to open it up an detach it's battery: it's an extreme way to get the job done, and (obviously) it worked :-)
Then after some searching I found a better way that doesn't involve dismantling the tablet: simply  push Vol Down + Power at the same time, and if you push then just after the tablet started the boot sequence, this should take you to the Recovery Mode menu, from here you can turn off the tablet: push the VolDown button until you see the "Power Off device" command, and then press the power button.

Reinstalling the update
After some  searching I've decided to simply retry to update the tablet, by sideloading the update with adb.
I've followed this guide.
Here is what I did:

• I updated my android SDK by using  SDK Manager.exe
• this may update the driver of your device, so maybe the computer wont see the device when you connect it: in this case you need to go in the "device manager" and force it to update the driver  (you can find the driver in "sdk\extras\google\usb_driver") you need to install the "Android Composite ADB Interface" driver, more info here
• I downloaded the file update for my tablet (see the linked guide for this)
• I rebooted my pc
• I disabled firewall
• I disabled antivirus
• I closed any running software (dropbox, skype, gTalk....)

Then I followed the guide: powered on the tablet, go to the recovery mode, open command  prompt on my PC, sideload the update with adb sideload command and... I got another error.
So I wiped the cache from the recovery menu, and tried one more time, just to get the same error again, something like:

Error!

bla...
bla...
bla...

Symlinks and permissions...
set_metadata_recursive: some changes failed
E:Error in /tmp/update.zip
(Status 7)
Installation aborted.

here is a screenshot of the full error message:

Reinstalling the update didn't work out, so I started looking for alternative solutions.
The only solution seemed to be to reinstall a factory image.
The issue with the factory image is that they will wipe your device, and I dont want to wipe my device because reinstalling and reconfiguring all the app take a tons of time (I have about 300 app on my tablet, with file manager, dropbox, synology cloudstation file sync, multiple account, multiple calendars, email, messaging...)

So I decided to try everything I can before doing a factory reset.

After much reading, I understood that it should be possible to install factory image without wiping the device. But to do this, you need to modify the installation script.
The procedure I'm going to describe here is a mix of the information I found on various website on the net.

Keep in mind that this procedure may not work, and it may brick your tablet/phone.
I'm not responsible of any damage/malfunction to your device.
Follow the described steps only if know what you are doing.

Steps to install a factory image without wiping your device
Download the factory image for your device from this page
Decompress it in a folder, and you'll have something like that:

Then you need to edit the "flash-all.bat"
The original "flash-all.bat" looks like this:

@ECHO OFF
:: Copyright 2012 The Android Open Source Project
::
:: Licensed under the Apache License, Version 2.0 (the "License");
:: you may not use this file except in compliance with the License.
:: You may obtain a copy of the License at
::
::      http://www.apache.org/licenses/LICENSE-2.0
::
:: Unless required by applicable law or agreed to in writing, software
:: distributed under the License is distributed on an "AS IS" BASIS,
:: WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
:: See the License for the specific language governing permissions and
:: limitations under the License.

PATH=%PATH%;"%SYSTEMROOT%\System32"
fastboot oem unlock
fastboot erase boot
fastboot erase cache
fastboot erase recovery
fastboot erase system
fastboot erase userdata
fastboot flash bootloader bootloader-grouper-4.23.img
fastboot reboot-bootloader
ping -n 10 127.0.0.1 >nul
fastboot -w update image-nakasi-krt16s.zip

echo Press any key to exit...
pause >nul
exit

This installation script will totally wipe your device.
I've highlighted in orange the culprit of the wiping.

The first orange line "fastboot oem unlock" will unlock your device.
I removed this line because I know that my tablet is already unlocked.
I know that unlocking a locked tabled will wipe all user data.

The second orange line "fastboot erase userdata" will erase all user data, to my undestanding this mean deleting your data/image/music/apps. So I removed this line because I want to keep all my user data.

On the last line I've removed the "-w" from the update command, the -w parameter tell the update command to wipe your device. And I don't want to wipe my device.


Here is my modified "flash-all.bat" script

@ECHO OFF
:: Copyright 2012 The Android Open Source Project
::
:: Licensed under the Apache License, Version 2.0 (the "License");
:: you may not use this file except in compliance with the License.
:: You may obtain a copy of the License at
::
::      http://www.apache.org/licenses/LICENSE-2.0
::
:: Unless required by applicable law or agreed to in writing, software
:: distributed under the License is distributed on an "AS IS" BASIS,
:: WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
:: See the License for the specific language governing permissions and
:: limitations under the License.

PATH=%PATH%;"%SYSTEMROOT%\System32"
fastboot erase boot
fastboot erase cache
fastboot erase recovery
fastboot erase system
fastboot flash bootloader bootloader-grouper-4.23.img
fastboot reboot-bootloader
ping -n 10 127.0.0.1 >nul
fastboot update image-nakasi-krt16s.zip

echo Press any key to exit...
pause >nul
exit

You CAN'T copy/paste this script, because it include path/filename/command specific for my device factory image (Nexus 7 WiFi v2012 Android 4.4): You should instead edit the script included in the factory image file for you device!

 

KEEP IN MIND THAT I'M NOT AN ANDROID EXPERT.

THIS SCRIPT MAY BRICK YOUR DEVICE

To my understanding maybe this script will work for you if:

• you are doing a "small" upgrade, like from android 4.3 to android 4.4
• you device is already unlocked
• you know the meaning of the following words: adb, sdk, command prompt, bootloader, recovery, locked/unlocked device, flash, partition, cache, firmware, root, mod, rom, hack

 This script probably will not work if:

• you are doing a big upgrade, like from Android 4.3 to Android 5.0
• your device is locked

This script is modified to try to not wipe your data, so it's totally possible that it will leave some unneeded file somewhere on your tablet.
I dont know if future OTA update will work. Update: my tablet just received the OTA update to Android 4.4.2, and it worked! :-)

As of today, this modified script saved me a tons of work: now my Nexus 7 is once again up and running, on Android 4.4.
Now it's unrooted, maybe I will try to reroot it in future.

In case you need it, here is a link to the linux version of this script modified in the same way by James Finstrom: it seem he is the only one that did something similar.

Feel free to ask any question in the comments.

Reblog: [H]ard|OCP - Microsoft Launches Kinect for Windows SDK Beta

Microsoft Launches Kinect for Windows SDK Beta

You know all those cool videos we post showing people doing neat stuff with the Kinect? Well, now you can make your own thanks to the new Kinect of Windows SDK beta.

via hardocp.com

Cool!

Reblog: What is the Best Way to Apply Thermal Compound? | Hardware Secrets

We already explained how the thermal compound (a.k.a. thermal grease or thermal paste) works and a “how-to-apply-it” in our How to Correctly Apply Thermal Grease tutorial. Now, we will try seven different ways of applying it, testing each way, and comparing the cooling performance. Let's see if what we always mention - that less thermal compound is better than more - is true.

Each different method is presented in three pictures, one of the thermal compound applied to the CPU before installing the cooler, one of the CPU after the test with the cooler removed, and one of the base of the cooler after the test.

via hardwaresecrets.com

A nice article with some real test about how to apply thermal compund.

Reblog: Understanding RAM Timings | Hardware Secrets

via hardwaresecrets.com

Reblog: Intel Announces first 22nm 3D Tri-Gate Transistors, Shipping in 2H 2011 - AnandTech

via anandtech.com

Reblog: Coding Horror

… I feel ethically and morally obligated to let you in on a dirty little secret I've discovered in the last two years of full time SSD ownership. Solid state hard drives fail. A lot. And not just any fail. I'm talking about catastrophic, oh-my-God-what-just-happened-to-all-my-data instant gigafail. It's not pretty.

via codinghorror.com

interesting post about SSD, and the fact that some of them seem to fail early