Firmwareupdate using USB

[kwriedel]

Hi, I got the 43 Vision "open", to show the hidden partitions, by copying the file Archos43.tab (search for "rkusb.tab") via USB to the Archos.
After reboot, the two hidden partitions are visible. Then making backups and deleting the four directories, I copied the directories
from another Firmware for the RK27xx (hopefully from the compatible Ramos T8) down there. All seems to be on right place.
Renaming the Archos43.tab to have partitions protected again.
After next reboot, the old stuff is back there again.

Any tips, to get the other Firmware running?
Or how to unpack the original Archos-Image file? Maybe any checksum check is done, so other firmwares don't run.
Or can anybody make a copy of his four Firmware directories?
My touch seems totaly misconfigured (and no factory reset...), so I have only access to device by USB.
Also I don't know how to use the RK27upgrade.exe. No futher success.