I've soft bricked my phone, stuck at:
Secure booting Error!
Cause : boot certification verify.
I rooted it using the E980 universal rooting tool from giantpune from ballshanglow's post. I then unlocked it using FreeGee 1.10, installed TWRP 18.104.22.168.
Upon reboot, the phone was stuck with the above error. I have downloaded the relevant .kdz for my phone, installed the USB drivers and the LG flashing tool. I have uninstalled and reinstalled the drivers (trying out different versions) and also tried various versions of the LG flashing tool (KDZ_FW_UPD_EN & FlashTool.1.0.54). I have also tried to use LG's provided software to recover my phone.
The furthest I've been able to go in the recovery/stock-firmware-flashing process, is the device check. Despite have 99%+ battery according to TWRP, I still get the error that my phone (in download mode) has low battery. Other times, the flashing tool freezes up and becomes not-responding after I get an extract error, or after I click 'Reading phone information'.
I've tried everything I could find. I've also attempted to flash a custom rom, but I get:
Assert failed: getpropr("ro.product.device") == "geefhd_att_us" ||
getprop("ro.build.product") == "geefhd_att_us"
E:Error executing updater binary in zip.
I'M F***ING STUCK. I'VE TRIED POSITIVELY EVERYTHING I COULD FIND.
Is there anything you guys can suggest I try before I send it to LG to have it returned to stock?
Thank you very much, and sorry I'm a noob. I tried.