Samsung LE40C659 goes ultrabright

[biljon]

I have a Samsung LE40C659 that functions normally for about 5 minutes but then all of a sudden goes ultrabright, you can hardly see anything because of the brightness.
It stays like this for maybe 30 minutes then goes back to normal for a short while, then it's ultrabright again.
I have checked voltages but everything seems normal.
Any ideas anyone?

[budm]

Re: Samsung LE40C659 goes ultrabright

Do you mean washed out pictures? How about upload he screen shot and pictures of the T-CON board?
It sounds like typical failed GAMMA Voltages.

[biljon]

Re: Samsung LE40C659 goes ultrabright

Thank you for your answer.
Here are a few pics.
First on of the t-con board, second is what it looks like when i start the tv, the third one is when it gets "washed out".

[biljon]

Re: Samsung LE40C659 goes ultrabright

Anyone got an idea what to do?