At one point within the last 1-2 years since I got xfinity,
it was nice with the menu of comcast labs and the signal strength check worked at one point.
It has not worked when I try it for at least the last 6 months,
always responds with
unfortunately we cannot check your signal strength at this time. please try again later.
the hold exit button 5 seconds, down arrow twice, then 2 does not work.