What does this error mean?

The error is:

avrdude: stk500_getsync(): not in sync: resp=0x00

I had an UNO board ("GEEKCREIT") that was working fine for several months in my application, which was to control a motor in a toy helicopter in a pinball machine (via relay board). All of a sudden after several months it stopped working completely. The first thing I tried was to re-upload the code to the UNO that was in the machine, which was connected via a shield and relay board. When I tried to re-upload the code to that particular UNO I got the compiler error mentioned above. I uploaded the code to a brand new, identical UNO board and swapped it out and it works fine. Even after removing the old board from everything and trying to upload/flash new code to it, I get the same error message. That being said, am I to assume that something on the board is toasted? In the application the only thing the board is connected to is through the shield to the relay board. It uses a USB charger for its power supply. This is the second board that has had this problem.

Any thoughts?

Have you changed anything on the PC meanwhile ?

  • if one is a clone it may not have the correct driver.
  • anything connected to the tx/rx pins will stop the usb working
  • you could try the loading the bootloader, using the other Arduino as the programmer ( if the bootloader is corrupted the USB port won’t work )

It means the computer didn t get the expected response from The arduino when it tried to upload. This coild mean the wrong board or port was selected, or any sort of hardware/bootloader issue from the serial adapter onwars. It is an extremely generic error message - the computer doesn't have any means to get more information in why it's not working.