I did as You said, but nothing happened.
The display just flashed 2 times, but the device did not reboot and the logo screen did not appear and the device can not enter the pre boot mode.
In the root of the SD card was created 41.bin file.
In the folder Garmin /Updater/0566 was created file last_id.bin and another update txt file with the content:

nüvi 310 Software Version 5.20, UID: 3325492249, HWID: 302520614
------------------------------------------------------------------------------
Parsing "rrgn,41,2:/41.bin"
Error
Parsing "xrgn,14,2:/14.bin"
Error
Parsing "reboot"
Success

What to do next?
Is there any way to solve this?