Because the Vim uses an IPEX type antenna connector, adding an external antenna is an easy project.
Also, when you get the Vim back on its feet, you can try this change and see if it helps.
From Android go to Settings/More Settings/About TV box and click Build number 4-5 times and it will enable Developer Options.
Back out to Settings/More Settings/ and click Developer Options. Scroll down to the Networking section. Turn on "Use legacy DHCP client". See if that helps.