How do I reset the AVR clock without disconnecting power?
A short push on the button switch on the AVR clock enters the Menu mode, advance to the Boot field (it will be flashing when it is selected). Another short push will active the Boot option, causing a system reset, initiated by the AVR. Shorting pins 5 (Reset, active low) and 6 (GND) of the ISP connector will hardware reset the AVR clock. Normally, no connector is present on your board, but you can solder in a 2-pin header. There are 5 columns of 2 pins each; use the middle column.