Unable to burn bootloader to Arduino Pro Mini

Projects General Guidance
1

Hello.

I have 2 Arduino pro mini, exactly the same as each other.

One of them, when I press RST button, the internal led doesn't blink, so I think it has problems with its bootloader.

I tried to burn bootloader on it several times using my another Arduino with this method.

IDE says bootloader is burned successfully, but when I disconnect two Arduinos and power only the damaged one, still its LED doesn't blink when I press RST, and I can't upload any program on it.

2

Move the broken one to your permanent external storage (aka your local dumpster) and grab a new one.

They're too cheap to spend much time finding faults unless you have a very clear idea on where to look.

3

Sound like there could be a fault in the download circuit and its connections to the processor.

You can find a schematic online of a standard Pro Mini, it might match the ones you have, or it might not.

Good luck tracing the fault.