Q: Very disturbed image with a macbookpro (only solution to get a normal image back: restart the computer) From where the problem comes?

Hello !

First, sorry for my bad english. I'm trying to use the correct words but maybe I'm not doing well.

I have a big trouble with the image of my macbook pro since one week.

Everything is fine on my computer then the image start to get mad (sometimes I see some horizontal fine dotted or continuous lines everywhere; sometimes grey scratch; sometimes the image start from the middle and finished to the left...)

It happens daily sometimes more than once in a day and it doesn't matter if i'm using internet or no or a software. It could happens whensoever [well, as I was writting: the computer just decided to do it right now -> the screen was totally blue and the computer decide to shut down and start again by itself]

I'm starting to get really worried.

My computer is a macbook pro from the end of 2011.

Os X El Capitan 10.11.4 (I have to say to you that I have a lot of problem since 6 months when I put El Capitan: a lot of bugs and the computer is really slow... I have a loading bar when the computer is starting! it's the first time in my life I see a loading bar for the starting, I didn't know it could happen before seeing this)

2,2 Ghz intel core i7

4 Go 1333 MHz DDR3

AMD Radeon HD 6750M 512 Mo

screen: 15,4-pouce (1680 x 1050)

Most of the time I have to restart the computer (sometimes I just suspend the activity and it's enough to have a normal image back)

When I restart the computer, it happens that it doesn't work: I mean the mac is not coming again. I have the loading bar of the beginning with the apple but it's never loaded. But when I start the computer with my windows partition it's always working. (and it's really fast) and it's really strange because I never had any problem on the windows part.

What kind of informations you could need ?

- Maybe is important to say that when I take a screenshot of the image problem, the image is totally normal on the screenshot. (I took pics with my phone in case of need)

- I'm travelling a lot (I'm in a different town every week) and I always take my computer (in my suitcase, backpack, brief case,...) so at the beginning I thought that maybe a component moved... but if something moved inside why the windows part is working well?

Thank you in advance to anyone who may be able to give me some ideas.

Cheers,

Lise