How do i hook up an xbox360 to model 6420FB? all we are getting is snow

snow is an indication of signal failure either from the station or an antenna connection problem
if it all channels then I would be looking at the cable connection at the cable box or outside antenna connections

Try website like Remotes.com to buy the tv original remote.

http://www.tradebit.com/filedetail.php/2997065-service-manual-sylvania-6420fe-color-television

YOU MIGHT NEED TO MAKE SURE ITS ON THE RIGHT CHANNEL. SOME TVS HAVE TV/VIDEO BUTTONS ! HAPPY HOLIDAYS!! HOPE THIS HELPS!!!

U can't get to channels 3 or 4 without a remote.Ur getting stuck on these particular channels 26,35 and 19 mean the last owner put these channels on the tv memory.Try website like Remotes.com to buy an exact remote or very close to the original,if u want make use of this tv.

now those tv cann't use without a digital converter box .call your cable provider for assistance

During a recent move the remote was lost. I have the 6420FF in my son's room and trying to set up dvd and wi console set up, but cannot adjust tv via menu button on tv. Is there any way to set-up game system and/or dvd without remote?

Unless the TV has a front-panel menu button and allows you to switch modes from there, you are out of luck. There are two possibilities. One is to try another replacement remote. If you get a universal remote made by the TV manufacturer (Magnavox), it may have buttons that will work. The other option is to purchase an RF converter, which will cost around $15. This will take the video/audio signals from the game and convert it to a channel 3 or 4 signal you can then tune in on the TV. The picture won't be quite as bright and clear as with direct AV input, but it will do the trick.

Trata con esto.
Presiona el boton Code search y mantanlo asi hasta que el led se quede encendido suelta y presiona el boton TV despues vas a presionar y soltar el boton Power hasta que el televisor se apague despues presionas el boton enter y el codigo queda almacenado.
El Tv tiene que encenderse primero manualmente.