Nedis video doorbell WIFICDP20GY

[peters]

There is a third board underneath the usb/SD card board.

There is a similar 5 pin but with different markings.

The doorbell is model WIFICDP20GY

[rubber_jonnie]

There is a third board underneath the usb/SD card board.

There is a similar 5 pin but with different markings.

I think without the schematic or a BoM you may be out of luck.

[peters]

This is the first time I've ever been able to see a blown component and it can't be identified. :-(

[rubber_jonnie]

This is the first time I've ever been able to see a blown component and it can't be identified. :-(

Happens a lot with blown SMD, they are so small the damage is too much to identify them. I had it with my old microscope, the LED ring stopped working and it was too damaged to ID. Luckily it wasn't an expensive scope.

[peters]

The RT1 component next to the blown chip is on the reverse of the board. When reassembled it would be inside the battery compartment right next to the li-ion 18650 batteries.

Could it be part of a thermal protection circuit ?

[rubber_jonnie]

The RT1 component next to the blown chip is on the reverse of the board. When reassembled it would be inside the battery compartment right next to the li-ion 18650 batteries.

Could it be part of a thermal protection circuit ?

Difficult to say without any knowledge of what RT1 is and what it does in the circuit.

[peters]

It's a black, bead like through hole 2 pin. I think it's a thermistor.

[rubber_jonnie]

It's a black, bead like through hole 2 pin. I think it's a thermistor.

Yep likely a thermistor, but unless it has direct connections to U1 you can't say it's related. I've looked for a schematic and can't find any, the best suggestion I can make at this point is to clean the burned part with a little IPA and take a close up photo of it so we can have a go at decoding what it is based on the markings that are left.

[peters]

There are no markings left, as soon as I touched it they crumbled.

IMG_20250318_140837062_HDR.jpg

There are a lot of voltage regulators like 3AC93, 3DE93 etc.

[peters]

I suppose the only hope is that someone else has a working one that we can get the component number from.