For information, this is the message I got when excuting the firmware upgrade.
The question still is : why this message as the firmware and the remote are RC5200 ??
Hope to have time to try with hyperterminal if I found what i should do but if the firmware I have are not compatible with my remote, I don't know what hyperterminal can do more..?
Any idea where I can find other firmware for my Marantz RC5200 ?
Thanks for your help !!!