Do you want to select the BOOT file manually? YES!
Operation: Repair Boot
Selected model: SM-T307U
Software version: 1.34
Setting up enviroment... OK
Waiting for EUB device... [Exynos7885] ... OK
Sending first loader... release power key... [SM-T307U] ... OK
Sending loaders... OK
Waiting for SBOOT device... found COM11
Handshaking... error(0.4.0004020D)
Operation: Repair Boot
Selected model: SM-T307U
Software version: 1.34
Setting up enviroment... OK
Waiting for EUB device... [Exynos7885] ... OK
Sending first loader... release power key... [SM-T307U] ... OK
Sending loaders... OK
Waiting for SBOOT device... found COM11
Handshaking... error(0.4.0004020D)