Hi. I have an Insignia HD TV, connected to a Scientific Atlanta Explorer 4250HDC cable box. I have an Xfinity remote (silver with Red OK button). I can't control either the TV or the cable with the remote. I watched this Xfinity video on youtube:
Insigina is really just a generic house brand, as such it's often made by other vendors for Best Buy. LG has been known to be original manufacturer of some TV's Best Buy sells. If you reply with your TV's exact model number it would help.
The fact that it cannot control the cable box is odd, since it should come pre-programmed to control Comcast boxes right from the local office. Perhaps the remote is defective? If you can't get anywhere with the manual telcodad directed you to, you might want to try getting a new remote from your local office.
You probably need to swap it if its not controlling the cable box. They should come default programmed for a cable box, maybe you have a remote for a different box than you have. it happens, I do not know about scientific Atlanta/Cisco boxes, but maybe someone else can identify if that remote has issues with certain boxes or something.
IF its a moto box and its actually light silver and not a darker charcoal grey it should control it by default, other wise there is a way to reprogram the grey ones to use the silver code, but you'd need an moto box for that and the color would have to be darker than the picture..
IE remotes 1 and 3 at this site. they look identical but have a slightly different base color.
If you think you have remote three, press cable then hold setup until it blinks, type in 982 then press cable and hold setup until it blinks [I think 4 times here but might be 2] type 01376 repeat the 982 step [first time unlocks the cable box code, second time locks it back down] its not necessary but it is protective.
On to insignia, they have several tv's made by various vendors and its not always published, I recommend using pressing tv, then hold setup until it blinks twice then enter 991, after that press 1. Now use channel up until the tv turns off, stop pressing, and press setup. test it with power and volume, if no go you may have over pressed the ch up button, go through 991, then 1, and press channel down once or twice and see if it turns off again it not start pressing up again until it does, whenever it turn off press setup.