My dad just bought a new TV and when we hooked it up to the receiver we noticed there was a slight lag between the lips of the people on the screen and the sound coming out of the speakers. It is using an RCA line from the DishNetwork box to the receiver and HDMI from the DishNetwork box to the TV. Any suggestions on what is going on and possibly how to fix it? The receiver is a Yamaha HTR-5740.
Use optical cable from DishNetwork box to receiver, if that does not work then try component video instead of HDMI, from box to receiver then receiver to TV. If that failed as well, then your box or receiver may have a problem.
Would having both optical and RCA connections cause the lag from having two inputs between each devices?
No, unless there's are problem with your unit.
You can try to figure out what's causing the audio lag but if optical connection from box to receiver doesn't work, check if your TV has optical SPDIF output and use it to send audio signal to your receiver.