Macbook Pro connect to HDTV gets pink display

I have successfully connected MB Pro to my HDTV using the Thunderbolt converter to the 15 pin cable needed for the TV.

When I have disconnected the Thunderbolt to take the laptop mobile then reconnected, the tv screen is magenta where it should be white. This happened once before and I played with it (have no idea what I did) and it went away but now it is magenta and nothing I do makes it go away.

This has to be a thunderbolt issue - I used an old HP laptop connected to this tv for about a year with no problems. This only happens after reconnecting the cable to the MB Pro.

Called Mac support and am very angry - my hardware is covered but its $49 to diagnose! Well that's not covered if it cost $49. There's no way its a software problem, it has to be the laptop itself but more likely the thunderbolt. I have turned everything off and on, disconnected and reconnected, nothing fixes it. Any help? Thanks

Very likely a defective cable or connector. That's a common symptom which will occur when a cable or connector is either loose or defective.

As for Apple charging you for the call, did you buy Apple care? Free telephone support expires after 90 days if you did not buy Apple care. The hardware is warranted for 1 year, 3 years with Apple care. And free telephone support is extended to 3 years. Which is why we advise folks to buy Apple care before the 90 days expires.