My U2312HM shows the pictures with a pink tone and stripes

Hi there!

I was a happy user of the Dell U2312HM until it starts to show some strange effects.
http://cl.ly/image/1k3F2g2v2N0o

It starts a week after the warranty expired (what a random) and I used to connect it to my Mac Book. It doesn't work properly with another connection (VGA instead display port) or another PC (Lenovo one instead of my Mac) so I think the problem comes from the screen. I also tried the colors test that Chris wrote in this post and the screen pass the test. During the first year alive I always used this monitor in the same way, as external screen for my Macbook, can you help me please? 

Thanks, Edu