I'm currently getting the "avrdude: stk500_getsync(): not in sync: resp=0x00" error message when uploading sketches. I have tried the following....
- Power to board, 'on' and 'L' LED both light up.
- Port correct as per Windows device manager (which shows 'Arduino Uno COM 3').
- Board set to 'Arduino Uno'.
- Nothing plugged into headers on board.
- Rx flashes three times, duration maybe in the microsecond range upon upload.
- Reset button does nothing.
- Neither does pulling pin 1 on the processor low.
- Pin 1 on the processor reads 5v so not stuck low.
- Loopback test passes fine.
The processor that used to work on the board stopped working when I measured the voltage between a GND pin and 5v to see how accurate a 5v it was for something else, it was the only regulated 5v I had to hand. I'm willing to accept I may have had the multimeter set to current but cant remember.
A new processor, preloaded with the bootloader gives exactly the same response as the old chip.
Is it likely the first chip died because I might have shorted the 5v header by accident (can't really remember, this was months ago now, I sort of put it away and forgot about it) and the 2nd chip doesnt actually have a bootloader on it despite supposedly being pre-programmed? Functionally the board powers up and both the USB and serial interfaces work.