KENWOOD DNX 8220BT garmin black screen PLEASE HELP ME!

Hello i have bought a used KENWOOD DNX8220BT from someone and now I discovered that all works but Navi (Garmin)
When I switch to Navigation I see only a black screen, I tried to download from Garmin site an update but nothing, when I put update file on SD it doesn't start to update. I think there is other problems, I read here on other topics about mass storage accidentally deleted and someone has lost everything. So I need to know if I could replace the original files from a backup for this device. Could I replace from other DNX? or must be from DNX8220BT only?

with garmin usb drivers and with a Windows 10 laptop I can access your device in mass storage mode.

So what I ask to someone who knows the matter, is how to do, by hardware and software. Hope I could do something to recover my DNX Garmin navigation software and make it work. Maybe I need to find GARMINCURE3. I read this:

"To make Garmin functional we have to use GarminCure3 for dnx7x20_dnx8x20_270 with Updater_exe.

Download GarminCure3 for dnx7x20_dnx8x20_260 with Updater_exe.rar"

but this file is no longer available there but I find here:
http://dl.dropbox.com/u/55759275/GarminCure3.zip

Please help me.

Thanks a lot