OK after over an hour and a zillion codes w/comcast cable tech
and finally my Insignia TV from best buy could be programmed
to my comcast remote!

We had to use a code for a SYLVANIA tv
Code: 0054

powered off like a charm!

press tv, setup (tv button lights up twice) then enter
0054 and press Power. It shuts off!

I was just about ready to put the darn tv back in the box and return it to best buy
for a brand that's easier to program!

hope this helps you as it did me!
Deonna