The speed of the resonator is 16MHz.The reset pin is currently tied up to 5V thru a 10K resistor.
You mean the 2560 is not using the resonator that is connected to it now?I have set no fuse yet at the moment, do I have to set any fuses and how can I do that?
Thanks for your reply.I have re-check and probe the wiring again and they are similar to JoeN process. In addition I have 3 x 0.1uF cap connected from AVcc to Gnd. I also have a resonator and a 1K resistor connected across the XTAL1 and XTAL 2. The datasheet of the resonator is attached.