I finally manage to fix the phone with the following procedure: First I somehow got a fastboot connection and reinstalled TWRP, as you mentioned, too.I‘ve had this problem too. What i did, is that I somejoe got a fastboot connection and reinstalled TWRP. The rom flash didn‘t work on TWRP, so I used SPFlashTool to flash the rom. At first it didn‘t work (sth like BROM_SEND_DA_FAIL) , but then I noticed that you need to check if the device is in the right state, there pops this Message up, telling you that a new device has been connected. If that pops up and the devices name is something with Mediatek or VCOM, your device is in the right state and you can start the procedure. After flashing the rom, everything should work as fine (first boot takes a bit long, don‘t worry). Hope this helped
---------- Post added at 10:41 AM ---------- Previous post was at 10:08 AM ----------
But there‘s a problem that I am having now, the device is in FRP mode after starting up, when logging in with Google, sth pops up and tells me to login with the owners account. Now I don‘t know what to do, can anybody help me??
Then I used the backup ROM for the first post, I copied it to a flash drive and I connected the flash drive to the phone via USB OTG. Then I restored this ROM from TWRP and the phone is working again!
You can try it, too!
