Trust Primo Touch Wireless Earphones

Original price: 29.99 EU, though now they seem to be available starting from ~19 EU.

This particular item was not charging at all. Box is held together by few latches and is easy to open.

Damaged IC: IP5305. Available on aliexpress, although I had second box from other set where one of the earphones was damaged/quiet, so I've just swapped it.

This cell looks swollen, although it does not seem to be the case and it accepted charging when I've detached it from the circuit.

KMT-F1 V1.4 2020-04-16

Four LEDs indicating charge level. Pogo pins charging earphones.

Location of the magnets.

After swapping charging box I've got working set. 
From the quick test - sound quality seems to be quite fine and earphones seem lightweight and convenient.

Measured time of music playback from phone with BT 4.0 at maximum volume: 1h50m (with few extra minutes left after power cycling). As maximum volume is pretty decent, using it for nearly two hours would be tiring/painful - in typical use these earphones would work longer.

It seems that these earphones enter pairing mode by default when there is no connection.

Excerpts from FAQ:

1. Turn off the Bluetooth connection on your connected devices (Bluetooth phone, tablet, etc.)
2. Take the Trust Primo Touch Earphones (both earbuds) from the charging case. Make sure they do not connect with any Bluetooth device such as your phone.
3. Double press only the right earbud, now the right earbud will be searching for the (so-called slave) left earbud.
4. The earbuds should be connected to each other within 30 seconds. The earbuds will prompt with a confirmation sound. After this you can connect your Trust Primo Touch Earphones to your phone as explained in the user guide.

If the earbuds won't link together, probably both earbuds are set as 'master', we advise the following to resolve this:

- Ensure that the earbuds are unpaired from all devices (phones, tablets, laptops, etc.), they were previously paired to.
- Put both earbuds back in the charging case.
- When the case has been fully charged, take one earbud (left) out of the case and connect it to your device.
- When this earbud has been succesfully paired to the device, take the other earbud (right) from the case so it will connect automatically to the other earbud and synchronise (wait for it to flash blue, not red / blue).
- Then both earbuds are linked and should work in stereo.

D-Link DWR 116 router

Hardware revision A2.

Three screws including two hidden under rubber feet.

Mediatek MT7620N

25Q64JV - 64 Mbit SPI Flash

W9425G6 - 32 MB DDR SDRAM, 16-bit

5V/2A power adapter included

MP1495DJ

Next to it: burned out SY6280 (for USB host port)

No visible damages beside burned SY6280 and power supply seems fine, but still very little activity on Flash pins - at the moment I gave up fixing it. Perhaps reading current Flash content should be next step.

MPOW D7 earphones

Inexpensive Bluetooth earphones.

Two earpieces connected with cable, buttons only on the right one.

Reason to disassemble: no sound from right earpiece.

Earphone turned out to be easy to disassemble.

Components on the PCB are covered with rubbery coating - this should be partially water resistant.

Left piece contains probably only LiIon cell (and obviously acoustic transducer).

Date on the PCB: 2018-11-14.

CSR8635 from Qualcomm.

Single microphone.

Unfortunately this is failure of acoustic transducer itself and from my experience they are pretty much irreparable. I might try to find matching replacement later though - it looks like there earphones can be reassembled without significant damage.

 

Logitech MX Master 2S

Logitech MX Master 2S with mechanically broken right mouse button.

This mouse can be paired with up to 3 receivers, either Unifying or Bluetooth. According to specification Bluetooth LE is required for second option.

Internal Li-Ion accumulator, charged with micro USB.

Two visible T5 screws and four Philips screws hidden under feet. Hooks on left and bottom sides, but easy to open.

"Hidden PCB" for button hidden in thumb reast.

500 mAh battery. Three leds with light pipes on left side indicate charge level. Operation time on single charge is specified as 70 days. Swappable (short instruction is included by manufacturer, though T5 Torx screws are not exactly user friendly) and and as it is not crammed can be probably swapped for third party higher capacity cell.

Very weird: there was extra screw stuck under battery holder screw. I don't think this was the cause of failure though as there seems to be extra space in this area. I'm pretty sure no one opened it before, so it must be manufacturing fault.

nRF 51802 - from Nordic site: general purpose, ultra-low power SoC ideally suited for Bluetooth® Low Energy and 2.4 GHz proprietary wireless applications. It is built around the 32-bit ARM® Cortex™-M0 CPU with 256 KB flash + 16 KB RAM. The flexible 2.4 GHz radio supports Bluetooth Low Energy and 2.4 GHz proprietary protocols, such as Gazell.

It incorporates a rich selection of analog and digital peripherals that can interact directly without CPU intervention through the Programmable Peripheral Interconnect (PPI) system. Flexible GPIOs enables you to connect digital interfaces like SPI Master/slave, TWI Master and UART to any of the 31 GPIOs on the device.

The nRF51802 is a low cost variant of the nRF51822, it has the same functionality, but has minor performance degradation in terms of:

• 2 dB less RX sensitivity
• Slightly higher RX and TX peak currents

BQ24040 LiIon charger

Pixart PMW3816DM sensor. Up to 4000 dpi according to specification and working on glass surfaces.

Motor has semicircular element on the shaft. After rotating it other plastic element is moved and mouse wheel is either freed or is resisting.

Broken right mouse button. I've used some epoxy glue and also heated this element with hot air (at 130 C) to adjust its shape/position.

There is also missing metal spring from the same button (probably lost at the same time button was broken). This changes the click feel, but still seems acceptable.

Hidden button (described as intended for gestures):

After repair: