980EXT OTDR Booting Bug Fix

After press booting button, power lamp is alive but display dosn't appear like the video in the link. This bug is because some system files were not loaded to memory of operation system correctly during the startup process. To solve the problem, users can press and hold power button for around 20 seconds, untill the device goes into repair mode. Then, the device will fix the bug by itself. Do not do any operations before the device turns off and turns on again by itself.