I am assuming that you have a gbuhd4k or gbue4k if you have multiple images on the box ???
So assuming gbue4K.....
If you cannot get telnet access then the box is in bad shape, so logs are probably not being stored during early boot up.
If you are using an internal HDD, it might be worth opening the box and removing the HDD connections - then stick a usb stick in the usb port and see if it boots... in which case its the HDD.
There is no recovery menu as such, unlike some of the zgemma boxes.
If you usb flash you should only lose the 1st slot (you used to lose all slots)