Question about Denver Frameo PFF-1010

Since yesterday, my Frameo no longer wants to start, i.e. it has switched on automatically as set, but it remains on the start screen with the red background and the Frameo logo. I left it like this for a few hours because I thought that maybe an update was running. Unfortunately, nothing happens after several restarts and also not after the reset attempt. Nothing can be found online and there is nothing helpful in the operating instructions. The Android menu that appears after the reset is also not clear how to operate it. Each press of a button only restarts the device, but I would like to boot with "Factory reset". The following options are displayed: ********** Adroid Recovery Any button cycles highlight. Long-press activates. Reboot system now Reboot to bootloader Apply update from ADB Apply update from SD card Wipe data/factory reset Wipe cache partition Mount / system View recovery logs Power off ********** Then it says at the bottom of the screen. ********* E: failed to mount /mnt/external_sd (No such device) E: failed to mount /mnt/external_sd (No such device) Supported API: 3 ********** I have never used an external SD card, not even to make a backup or anything like that, and every time I enter the menu with the "long press", a reboot is performed before I can even select another menu item. If anyone has a solution, I would be very happy. Thank you!