When the arduino burns a bootloader does it set the clock to 16MHz external?
I will try to locate a crystal, I think I have one somewhere.
Any reasonable clock signal (e.g. 1 MHz) on the XTAL1 pin will work to reprogram the processor. Somewhere in the forum is a modification to the ArduinoISP sketch that provides a 1 MHz clock just for that purpose.
But even if thats the problem why can't I access the fuses with avrdude?
I have no idea if it is or is not true but my suspicion is that the processor has a "micro kernel" that executes ISP instructions. In order for the "micro kernel" to run, it has to have a clock.
In any case, a clock is required for the ISP interface to work. There is a very very tiny bit of detail in the datasheet on page 230...
[diagram shows a clock signal arriving at XTAL1]
Notes: 1. If the device is clocked by the Internal Oscillator, it is no[t]
need necessary to connect a clock source to the XTAL1 pin
Keep in mind burning bootloaders and using avrdude is all new to me.
At some point, it was new to each and every one us. Not even the folks at Atmel were born knowing how to burn a bootloader.