I have a Nano which fails to verify though others do verify correctly.
I attempted to program 'blink' and the LED doesn't respond correctly.
Attached is a copy of the programming messages.
Do I need a new Nano or should I attempt to reprogram the bootloader?
I have another nano and a uno - I guess I could use either?
The board doesn't have ICSP pins soldered and if I fitted them I would have to remove them again or it won't fit on the application board.
So must I use the ICSP pins or can I connect to the equivalent pins - D11, D12, D13, RST, +5V, GND?
Device sig 0xFFFFFF can mean that MISO is shorted to Vcc (or you wired it wrong) - Doublecheck connections with your DVM before you trash the nano. Also check that all the applicable pins are connected (for example, if Gnd wasn't connected, but Vcc was, I think you'd get this result too). I recommend always doing this when there are inexplicable problems bootloading - particularly when using Arduino as ISP, since there are twice as many connection points to screw up.
(also, a trick relating to ICSP headers - if you have a cable with 2x3 connector on it, you can plug a 2x3 piece of pin header into it, put it into the holes, and hold it in place, with a gentle sideways pressure to make sure the pins make contact - that's how I bootload the boards I sell)