I got a batch of pro-minis with ATMEGA328P chips on them that will only load a sketch when the ATMEGA328 3.3V 8MGHz option is selected in the arduino IDE.
I tried burning a new bootloader for the Uno to fix the bootloader bug in the pro-minis that prevents a wdt reset from working, and it refuses to load a new sketch. I tried re-burning back to a 16MGHz pro-mini bootloader, and it still won't load the sketch. Only when I put it back to the 8MGHz 3.3V version will it load a sketch.
Can someone please tell me why this is the case, and if there is any way around it to get the Uno bootloader on these chips?
Thanks in advance.