Save the Exploding Bluetooth Keyboard! ! ! No rollover! ! ! Share ideas and practices! !

A classmate's bluetooth keyboard suddenly exploded while charging. I saw my fat brother repairing the keyboard a few days ago (the time when the car overturned), so I asked my fat brother to help him repair it. .

There is one thing to say, before repairing, it is generally necessary to listen to the operation before the damage. This allows the location of damage to be identified.

The fault description is that when it is charging, it explodes all of a sudden.

Charging and charging, there is a high probability of damage to the power management IC, a small probability of damage to the lithium battery, and a small probability of damage to other components. You can know it when you disassemble it. Without further ado, the picture above.

You can see that the PCB below has burnt marks. . . The chip in this place has been burned through. There is a high probability that the charging ic will explode, probably because a fast charger is used. . . It's outrageous. . .

There are two solder joints on the pcb, one vbat and one gnd, VBAT should be the abbreviation of VBATTERY, the battery terminal, and GND is the ground.

Use a DC power supply to add electricity to see if there is any damage elsewhere. To be on the safe side, start with 2V and add to 3.5V.

The power supply used for powering up should have been seen by engineering friends doing experiments. .

Schematic diagram of power-on.

After the power is added to 3.1V, the light is on, and the visual inspection is that the power management IC is damaged. But everything else is intact, and the Bluetooth keyboard can be used normally, but the charging IC is broken, and there is no substitute in hand, what should I do? ? ?

After communication, the students asked that it only needs to meet the daily use functions.

Just let this bluetooth keyboard can be charged and charged.

Don't be afraid, don't be afraid, the engineering fat brother is fearless.

After analysis, the lithium battery is 3.7V, and there is a protection board inside. It can be directly connected to the power supply for charging, the voltage is set to 3.6V, and the current is charged to 50ma, which is considered to be fully charged.

Then just make a mother-child terminal between the battery and the board, and the terminal is drawn out. When charging is required, disconnect the terminal and power on to charge the lithium battery.

let's move! ! !

The terminal on the lithium battery, the male terminal.

Female terminals on the board.

Open the shell with a soldering iron. It's not pretty, but it works.

Combine! !

Secure the wires with electrical tape.

Assemble, the sides look like this. It's ugly, but it doesn't affect functionality.

In the front view, the switch button was burned and deformed, so it was thrown away.

long tail! !

There is one thing to say, the fat brother's technology is not bad, the car rollover is only a small probability event, thank you for watching and reading! ! !