NSA325 booting problem (1 reply)

Hi,

i've a problem, i'm thinking that i've bricked my NSA325.

For several months all works fine. Yesterday, having a lot of time i thought "time to update".
I updated debian whezzy to jessie and the kernel 4.4.0 to 4.5.0. After rebooting booting fails
Begin: Running /scripts/local-block ... done.
done.
Gave up waiting for root device. Common problems:
- Boot args (cat /proc/cmdline)
- Check rootdelay= (did the system wait long enough?)
- Check root= (did the system wait for the right device?)
- Missing modules (cat /proc/modules; ls /dev)
ALERT! /dev/disk/by-label/hdd-root does not exist. Dropping to a shell!
modprobe: can't change directory to '4.4.0-kirkwood-tld-1': No such file or directory

I've seen the new uboot 2015-10 and tried to update my older uboot 2015 (don't know why i thought, that could solve my problem)
All seems to have gone fine but after reboot the box didn't work anymore.

The box starts, shows the blue button and the green led hdd2 turns on, and both stay turned on for about 20-30sec.
The they turn off for 1sec and return on. This continous....
I tried to connect via serial cabel but putty doesn't shows any message.
The only "change" is, that the serial converter's led for "data" turns off when the box has startet. In the 1sec the box "reboots" the data led turns on and off again.

Is there any chance to unbrick the box or to look for what happens?

Thank you in advance!