My broadband has connected but the signal it to weak a d I have on TV glass or internet

[Zig]

Our broadband has been down for past 3 days and has now just reconnected, however the signal is so weak it will not connect to the internet and we have no TV. The small box on the wall that the engineer put in is only showing 3 lights 

The router is showing 4 lights. We normally have super ultra fast speed around 840 MPs it now shows 1

[Highlinder]

@Zig  The box on the wall is only supposed to show 3 lights and the router having 4 lights in also correct.