i have h815 5.1.1 with locked bootloader. when i heard theres a MM 20b available, i tried to update my phone, losing my root access.. i just played around for a while and was not so happy yet, that i decided to downgrade back to my old FW. (10e). i flashed back my kdz using LGUP using refurbished method. and now the problem starts to come in.. after flashing back, i rooted it again, then it starts to have bootloops.tried to look for another open kdz to flshed but didnt worked out.. when i tried to flash back again 20b, i cannot enter download mode anymore, still getting in recovery though, i tried to clear data. but still not booting up. LGUP is not seeing my phone and also flashtool 2014. please help.. 
Sent from my SM-N9005 using Tapatalk
Sent from my SM-N9005 using Tapatalk
