hope can get here more help

First of all, the Box worked! After an successfull Update i forgotten a insert MicroSD in the slot (with twrp on it - if this could be the reason) and somehow i get stucked at a blank, black screen.
No Logo, no recovery, nothing....
Tried out to flash "blind" via SD Card method with help of Burn Card Maker, seems that worked - cause i see "boot" and then Clocktime on LCD , but farther no Screen.
Also flashed via Male to Male USB Cable and USB Burning Tool 2 different Stock Firmwares (X96_Max_V311_S905X2 & X96Max_2G_20190223) - no change of screen...
Now i don't have more ideas anymore, somebody else?
Hopefully TeVioN