Downloaded it twice from ICOM Japan...extracted to the SD card as per the instructions.
Not too sure....whats the difference between USA and non-USA firmware? I'm in Canada so I'm left wondering what I should use. I tried the USA rev first...which failed.
USA firmware is written to run on R8600's with a serial number starting 02, non-USA runs on, I think, all others. The 02 block is the US specific, cell blocked, version. So look at your serial, if it starts with 02 use the US firmware version, if it starts with anything else use the non-US version.
Other than that make sure you are not trying to run the 1.20 version updater of the CS software thinking it is the R8600 firmware updater.
T!