How to burn Arduino bootloader to Pro Micro by Nano.
So, you need to burn bootloader to Arduino Pro Micro. You have good Arduino Nano.
Connect Arduino Nano to PC.
Open Arduino IDE 1.8.5
Arduino IDE: Tools-> Select Board -> Arduino Nano
Tools->Processor-> Atmega328p (old bootloader) # I buy board made in China
Tools->Processor->AVRISP mkII
Open File->Examples->11.Arduino ISP
nothing changes
Upload Sketch
Nano | Micro
GND - GND
5V - Vcc
D10 - RST
D11 - 16
D12 - 14
D13 - 15
+capacitor 4.7mkF-10mkF between GND and RST (check polarity!) for Nano
remark: if you have Nano 3v3 version,
Arduino IDE: Tools -> Select Board -> Arduino Micro
Tools -> Programmetor -> Arduino as ISP
Click: Tools -> Burn bootloader
Wait about 1 minute.
2 LEDs on Arduino Pro Micro will fired when finished.