There should be no need to use the reset button.
The CH340 DTR line is connected to avr reset, avrdude knows to assert this line to reset the controller to start upload.
This can bee seen on the last page of the circuit diagram [
github.com]
You either have a hardware fault or the boot loader has been damaged,
Install stock atmega2560 boot loader, using a avrisp. see [
sparkfuneducation.com] as one example on how to do this.
Edited 1 time(s). Last edit at 11/26/2024 05:51PM by Dust.