How to load the bootloader for new ATmega 328P U chips
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1. Put the new chip on a breadboard, connect it to the parts listed below and an Arduino UNO board with a functioning 328P chip.
The two caps can be 22pF or 20pF as well.

The pinout of the 328P chip:

Go to File - Examples - ArduinoISP - ArduinoISP

Also, make the following selections:

Finally, burn the bootloader:

After this is done, swap the newly loaded 328P chip on the breadboard to the Arduino UNO board. Use the 'Blink' example to test if the new chip can be programmed.