Hello.
Please try to use another USB A-B cable; try to connect Box to another PC motherboard USB port (don't use any USB hubs, this is important for stable connection). Try to use Box on another PC.
If the problem is still the remains, most likely Box has HW problem (problem with USB A-B connector or another problem). If your Box is still under the warranty, please contact to your reseller and change Box to another. If warranty is already expired, You can send us your Box and we will repair it for free, but You should pay for both way delivery (note, that this can be more expensive than buying new Box).
Also, You can buy new Box without card (Medusa Box Upgrade Kit), please look here:
https://gsmserver.com/item/boxes-and...o-upgrade-kit/.