For a project I've been working on, I've re-designed a working PCB schematic so that it uses all SMD components and now features an ICSP header. The board is essentially an LED driver controlled by an ATMEGA168. It is Arduino compatible and the PTH version works fine.
I've assembled the new board, but I cannot seem to program it using my AVRISPMkII. Since this is the first time I've done anything like this, I'm struggling to figure out where to start when it comes to debugging the board. When I'm trying to communicate with the board, I get one of two error messages. These are:
avrdude: stk500_getsync(): not in sync: resp=0x00
avrdude: stk500_getsync(): not in sync: resp=0x66
As far as I'm aware, this fault is due to not being able to communicate with the board. I was wondering if this could be because I've damaged the ATMEGA while soldering, messed up the circuit design or something else? How can I debug this sort of thing?
[Edit - removed the link to my schematic for privacy, now the problem is solved]