Trying to use rgb input

Try changing the input on the television with the remote or on the television control panel. Apparently you don't have anything plugged into the RGB connections.

It sounds like the computer is sending a signal to the monitor, but the monitor is not happy with the signal.

First, I'd check the cables. Make sure they're all plugged in solidly to the right ports. If you have a spare cable, swap it out to see if it helps. Note that Component Video is not the same as RGB, so you can't just plug an RGB cable into Component jacks.

Did the monitor come with software that needs to be installed? Make sure that's installed.

Check the monitor manual for what kinds of input it can accept. Check your computer's manual for what kind of video output it can produce. Make sure you're using a protocol that both can work with.

Try connecting the monitor to another computer. Maybe the monitor is faulty.

Try using a different video protocol. If you were using your computer's HDMI port, does it have an RGB port? Can you use USB?

Turn on the TV again. You need to change the input from RGB back to cable or HDMI or Component or whatever input you have a source for. If you don't know which one, look at the back of the TV and the wires you've got plugged into it.
If it's 1 round coaxial cable, change the input to Cable.
If it's three wires (red, white, and yellow) change the input to A/V.
If it's 5 multicolored wires, change the input to Component.
If it's an HDMI cable, change input to HDMI.
If you cannot change the input before the TV turns itself off, try unplugging the TV from the wall socket for about 10 seconds, and then plugging it back in. If its still on RGB, you're going to have to either find a way to get faster at switching inputs, or find an RGB cable and something to connect it to your TV. This is a last resort however.

More info is needed, please. When you say 3 video inputs, what are you referring to? I believe the Sanyo has the HDMI, RGB/YPbPr component video, S-video component, RCA composite video and Coaxial connections, though I'm not sure how many of each. So lets start with the best quality to least.

HDMI: This is one cable that provides both audio & video and produces the best picture quality. It comes in different lengths and is a wide, flat connection. A must for 1080p resolution signals.

Component video, RGB or YPbPr analog component cables: 5 separate RCA cables, 3 of which are video that separate the video signal & 2 audio cables. The 3 video cables are generally red, green and blue (RGB) or marked individually with the letters Y, Pb/Cb & Pr/Cr . The audio cables are red & white. You may see these on the back of DVD players often. They will carry a signal up to 1080i but not 1080p.

S-video component: One cable for video, it is a round connection with several pins in it and will only plug in one way. You must use 2 RCA cables for audio with this cable, red & white again.

Composite video: 3 separate cables; Red, White & Yellow. Red & White are audio, left and right while yellow is video.

And finally there is coaxial which it the cable that is identical to the cable from the pole/ cable box or your dish. It is the poorest quality.

What can happen is you are using 3 standard RCA cables and have them plugged into the component input & they will not carry the signal, or one end in component input and the other end in the composite output or vice versa. Another is that you have the wrong input selected on the menu. Check all your cables and connections, plus the input you have selected on the TV itself.

Couple of items come to mind.
In the menu of the receiver, is there a way to choose video and RGB?
Set the receiver to SAT
Connect the HD Cable Box to SAT
Check the TV is on Monitor RGB.
Check the input being used by the monitor RGB cables is selected on the TV.
Have a picture? NO, receiver has issues.
Yes? Do this with each input to confirm they work.
You can reset the whole receiver to factory by holding the tone button down and holding the standby button for three seconds. (This clears your speaker setups, too.)

you are unable to get an image on your ViewSonic monitor, first check that the necessary cables are attached correctly and that the proper drivers are installed. ViewSonic offers drivers for download directly through its website (see Resources).

Some LCD monitors use a VGA input while others take advantage of the newer DVI interface to provide a connection to PCs (some ViewSonic monitors offer both types). When connecting your monitor for the first time, you'll need the right type of cable for both your monitor and computer. In some cases an adapter may be necessary to convert the DVI signal from your monitor to work in a VGA input on your PC.

Check that the VGA or DVI cable is tightly attached to the back of your monitor and to the back of your PC. Use the small thumb screws on the ends of the connectors to keep everything tightened in place, which will prevent the cable from getting loose.

ViewSonic monitors also use a power cable to plug into a power source. If the power light does not comes on, check that the power cable is inserted fully into the back of the monitor and that it is plugged into a working wall outlet or a reliable surge protector.

bad tunner in tv

sounds like bad tuner