no light no power

[lux]

Tello won't power on

I have two batteries and they are all fine
It works fine on other Tello

The broken Tello does not light up in any case even if the external power is connected and the battery is charged

Is there anything I need to check

 

[quaddamage]

Nothing special in Tello in regard to fixing; go as with any device:

First thing is to check power delivery. You need a multimeter, and check test pads on the board.
I don't think we have the voltages for reference, so you need to compare voltages to known working board.
(unless you can find such reference - some repair technicians do publish such info)