SRX 100 cli dead - /bin/csh: Input/output error

Hi folks,

I have a strange issue on one of my SRX100 Devices:

Whenever I try to login with the root-user I get: /bin/csh: Input/output error ***Session End***

I can login with any user but as soon as I try "start shell", regardless of the user, I get the same /bin/csh: Input/output error and the cli never starts...

I tried rebooting - no success

I have some other SRX100 that work fine - is there a way to "recover" the SRX via USB like the J-Router Series, where you can create a "boot-Stick" with a working Device? Or is there another way?