Are you using a Cable box, Fiber Optic box or Satellite box? That would be an issue with your satellite/cable/fiber provider.
Even if it is a direct connection and you use a CableCard. That would be a signal issue from your provider. Although you may have to play phone tag between Phillips and your cable provider.
You may need a signal booster. This is what I use. If you have cable internet you'll want want like this with a modem bypass. If you have multiple TVs you probably could use a booster. Your cable provider will install one but you'd have to pay a support call. Which may be best as the wiring can be a pain. Wherever your cable lines are split is where has to be installed. Usually this is outside, in the basement, crawlspace or...