My gt5662 doesn't see my tv using hdmi

Sounds like a main board issue.

If you hooked up with set and or a box on that may be the issue--HDMI does not like connections being made with units on.

disconnect power from set and or box if used for a while and then with HDMI reconnected power up the set and or box.

When you have everything connected try turning your TV off then on . My laptop dide the same thing and this is how I solved it...

If it's the first time using your PS3, use the composite cables that came with it. Turn on the PS3 go to video settings and switch the input to HDMI. After you've switched to HDMI, turn the PS3 off and connect your HDMI cable, go back to video settings and change the resolution to 1080p. If this isn't the first time you've used HDMI for your PS3, make sure your T.V. is on the correct input. If the T.V. is on the correct input, try switching the HDMI cable to a different input. If that doesn't work try using a different HDMI cable, testing different HDMI connections if you're still getting the black screen. If none of those work then it's probably a problem with the PS3, but just to make sure try plugging something else with HDMI to see if that works. If another HDMI device works, then it's your PS3, if it doesn't then it could be a problem with your HDMI connections on the T.V.

If you just bought the PS3 use your composite cables that came with the system. Turn the PS3 on and go to the video settings, set up video input to HDMI. After you've done that plug your HDMI back into your PS3 and try turning it on. If that works go back to video settings and change the resolution to 1080p. If that doesn't work make sure your T.V. is on the same input that the HDMI cable is plugged in. If it is and still doesn't work try switching to a different HDMI port. If switching to a different HDMI port doesn't work try a new HDMI cable. If the new HDMI cable doesn't work then there is a problem with the port on the PS3 which would require a repair.

Try using the "source" or "input" button on your tv or remote control. That will cycle through any ports that are being used (hdmi, component, rca, etc)
Hope this helps!

Best way to attached with HDMI.Its very easy to use just input and select HDMI port number from TV like one or two. TV Network Mostly use for internet videos or for IPTV. Best use with HDMI.

bbutler,
Your Toshiba can handle PC screen resolution up to 1024 x 768
Lower the resolution of the PC screen to somewhere between "640 x 480" and "1024 x 768". It will work just fine.
It's not likely that there is a any physical problem with either the PC or HDTV.
1. Right-click anywhere on your desktop
2. [Properties]
3. [Settings] tab
4. Slide the "Screen Resolution" pointer to the LEFT to adjust and click on [OK]
*DONE*

Something is wrong whith the HDMI jack it's self, or the electronic switching is not sensing a signal is present. In either case the board that has the HDMI jack you are using needs to be replaced. Most all these boards are double printed, Multi-layered or both which prevents replacing the jack it's self. I do have a question though, do you only have on HDMI jack on the unit or do you have another one available.