Arcadyan ARV752DPW22 (Vodafone EasyBox 803A) firmware deleted?

I tried to install openwrt, with a serial cable:

I played a little bit and I get this:

Enter Administrator Mode !

 [#] Set Serial Number
 [2] Use Normal Firmware
 [3] Use ART-Testing Firmware
 [9] Taggle ART Firmware Enable/Disable
 [A] Set MAC Address
 [B] Set WPA Key
 [E] Erase Flash
 [G] Run Runtime Code
 [H] Set Options
 [M] Upload to Memory
 [P] Print Boot Params 
 [R] Read from Memory
 [T] Memory Test
 [U] Upload to Flash
 [V] Set Board Version
 [W] Write to Memory
 [Y] Go to Memory
 [Z] Dump DDR Ram Register

[DANUBE Boot]:

But I cant upload a u-boot image, anymore. Getting Errors:

Wiederholungsversuch 0: Sektor nicht bestätigt
Wiederholungsversuch 0: Sektor nicht bestätigt
Wiederholungsversuch 0: Maximale Wiederholungsanzahl überschritten

When I reboot the device, I get this Webinterface:

Can anybody help? Or have a working original firmware?

These devices are quite old and got very little testing by OpenWrt developers and -users, while most were (and partially still are) concentrating on the significantly better vr9/ xrx200 target instead. Documentation is accordingly sparse, where it exists at all.

Without diving much deeper into the topic (I never owned the device in question), I really doubt that current OpenWrt fits into its 8 MB flash (of which quite a lot is used for other (phone-) purposes), so getting it to build is probably going to be quite ambitious - and hardly worth the effort.

The good part, if you have your backups in line, these SOCs are rather hard to really brick, allowing to restore the flash via serial console.

It was my fault. The device is not bricked. I have to close screen/minicom before I can upload uboot. Uboot works ... But what's next?
It must be possible, to install openwrt 23.x on this device.
Look at here:
I have a seriel/usb converter, too.

That's what the link is describing?

What you mean?

... the installation procedure?

Yes, but at the moment I don't quite understand the procedure.

I recommend this instruction:

Thank you. But now, I think, I have realy brick the device. When I turned on the device, nothing boots ... :frowning: