Sorry for the trouble caused.
For the wifi issue, please check the USB port on the unit, just plug an USB stick with some music or video.
If the USB still work, you can use the wifi dongle to get the wifi signal again, but please notice not all of the wifi dongle work with the unit.
Here is the link for your reference.
https://www.amazon.com/TP-Link-Wireless ... +TL-WN823N
This unit does not support to directly upgrade to Marshmallow.
RegardsStatistics: Posted by Jammy — Fri Apr 07, 2017 6:26 am
]]>