My SONY 3LCO Wega Engine TV is having a problem with the HDMI inputs I plug the HDMI cable (For video 7) And when I turn on my PS3 it shows up a bunch of pixels and says ''Unsupported Signal, Check device output'' .. And for the HDMI slot for video 6 it doesn't even work.. Like when I plug it in and go to Video 6 nothing shows up.. PS. It use to work, I've tried 3 different HDMI cables. And it also works on other TV's.

SOURCE: PS3 no longer communicating with TV

All: Try this -

Perform the following steps to reset the Video Output Settings.

1. Make sure the HDMI cable is connected to the [HDMI OUT] port on the back of the PLAYSTATION 3 system. Connect the other end of the HDMI cable into the [HDMI Input] port of the TV or display monitor.
   
2. While the PLAYSTATION 3 system is in standby mode (red light on the front of the system), hold down the touch-sensitive On/Off button on the front of the system until the system goes into standby mode again . (So the light cycle would go from: red light to --> green light --> then back to red light) This will ensure that you have held down the On/Off button long enough to reset the Video Output Settings.
   
3. Turn ON the PLAYSTATION 3 and once the system finishes powering up, the Video Output Settings will automatically reset to the standard resolution (or detect the current display output settings of your TV/monitor). [If resetting does not auto-detect your HDTV, see next step below.]

NOTE: As of system software update version 1.60, the PLAYSTATION 3can automatically detect an HDMI connection to a TV. If the PLAYSTATION 3 is turned on with an HDMI cable connected, the screen for switching video output settings will be displayed automatically. (Does not function unless the TV that is connected by the HDMI cable is turned on.)

As of version 1.80 of the system update for the PLAYSTATION 3, the PLAYSTATION 3 can upscale the video content of PlayStation® format software, PlayStation®2 format software, and DVDs to HD resolution.
If Resetting the Video Output Setting Did NOT Detect Your HDTV Automatically (Certain TV's Only)
With certain televisions, the PLAYSTATION 3 may not automatically detect the HDMI source (TV) which it is plugged into, even after resetting the Video Output Setting (as described above).

If resetting the Video Output Setting did not work, you may need to follow these steps to manually locate the HDMI source:

1. Connect both the AV Cable and the HDMI cable from the PLAYSTATION 3 to the corresponding (AV and HDMI) ports on your TV. 2. Proceed with resetting the Video Output Setting on the PLAYSTATION 3 again. (Follow these steps, then continue to step 3 below.)
3. Turn the TV channel to the corresponding "Input" or "Video" channel for the AV Cable connection.
4. Manually change the Video Output Settings to HDMI. (Follow these steps, then continue to step 5 below.)
5. Now switch the "Input" or "Video" channel on the TV for the HDMI port the PLAYSTATION 3 is currently plugged into.
6. Accept the display settings for HDMI before the timer runs out (30 seconds). Highlight "Yes" and press the X button.
7. You can now disconnect AV Cable from the PLAYSTATION 3 and the TV, as it is no longer needed.

With certain televisions, the PLAYSTATION 3 may not automatically detect the HDMI source (TV) which it is plugged into, even after resetting the Video Output Setting (as described above).

If resetting the Video Output Setting did not work, you may need to follow these steps to manually locate the HDMI source:

1. Connect both the AV Cable and the HDMI cable from the PLAYSTATION 3 to the corresponding (AV and HDMI) ports on your TV. 2. Proceed with resetting the Video Output Setting on the PLAYSTATION 3 again. (Follow these steps, then continue to step 3 below.)
3. Turn the TV channel to the corresponding "Input" or "Video" channel for the AV Cable connection.
4. Manually change the Video Output Settings to HDMI. (Follow these steps, then continue to step 5 below.)
5. Now switch the "Input" or "Video" channel on the TV for the HDMI port the PLAYSTATION 3 is currently plugged into.
6. Accept the display settings for HDMI before the timer runs out (30 seconds). Highlight "Yes" and press the X button.
7. You can now disconnect AV Cable from the PLAYSTATION 3 and the TV, as it is no longer needed.

SOURCE: ps3 sony grand wega (4 yrs old)

Press the input button on the tv itself to select the proper input you desire.

SOURCE: Sony KF50we60 hdmi-dvi sound cuts when plugging into a ht-sf2300

DVI = HDMI without the audio connectors. So basically you need to connect your audio in some different way, PS3s allow you to keep your video signal as HDMI and change the Audio signal to component, so that is one way or doing it, not sure if the blue ray players allow you to do this though.

SOURCE: sony bravia klv-32t400a hdmi input through x-box

The problem is that, according to the specs for that TV, it doesn't support 1080p.
That's a 720p television you've got. (Specs here)
While the specs say that it supports 1080p, the resolution says it supports 1366 x 768, which is only 720p, not 1080p or even 1080i.
You may want to contact Sony for clarification, because their specs for that tv are contradicting each other.

SOURCE: PS3 No signal to the TV

To solve this, when the ps3 is in standby (solid red light), just hold the power button. It should beep on, then beep again in about 5 seconds. This will automatically search for the optimal audio video output. if if beeps on then turns off, just try again, it takes 1 or 2 tries sometimes. the reason this is happening is because your ps3 is set to one AV output, ex. composite(red yellow white), HDMI, and then you changed the cable to a different one. another way to fix it is plug both cables, HDMI and composite, into the tv and ps3, then go to settings and change the output to the desired one.