Tp-link Mr3420 V5 Firmware |top|

"It won't recognize the new LTE modem," Elias muttered, staring at the blinking red light. "The hardware is fine, but the brain is out of date. It doesn't know how to talk to this USB stick."

Go to Advanced > System Tools > Firmware Upgrade (some menus may vary slightly). tp-link mr3420 v5 firmware