Welcome to the
Kitz forum.
From the information you have shown, it seems as if either the boot-loader has become corrupted or the system image is missing.
Unfortunately the
Huawei HG8245GTH is not a device with which we are familiar; I believe it is a variation of the HG824n ONT range. Perhaps it is a device specific for Bulgarian service providers?
Here is a
list found by searching on the string "
HG8245". (Searching for "
HG8245GTH" or "
Huawei HG8245GTH" does not find anything of interest.)