MBP 15" mid-2010 screen shows strange colors

Hi everyone,

This is the first time I'm posting something here so I hope I do everything correct!

Some time ago (around 4 weeks I think?) I brought my notebook to the Apple Store because of freezes. They concluded the logicboard was fried so they replaced it. All was well, until a couple of days ago.

Out of the blue it started to show strange colors (red, green, blue stripes) on my screen, like an old television that needs a slam so it works again (of course I haven't done that to my notebook...)

Sometimes it's there, sometimes it isn't. So I called with tech support and they helped me reset PRAM and SMC (right?) and I thought it was gone until it happened again.

So I tried to think and I thought maybe it's the connector of my GPU to my logicboard... When I give a ultralight push on the left speaker (under it is the logicboard), the screen returns to normal. Of course when I release it, it comes back. Now for example it isn't there, but maybe in a couple of minutes it will be. Totally at random. Also lightly touching the bottom makes the colors go away and come back. Only if I touch it on the logicboard side.

I made an appointment at the Genius Bar as I still have guarantee, but it's on monday... And I need to finish something this weekend on my notebook. So my question is: is it indeed a cable/connector and can I still use my notebook? Or would it be something else which requires total rest for my laptop? They couldn't tell me over te phone...

If you ask me, touching something which then makes it work sounds like a connector that's not in place or something...

If anyone has experience with this or tips, let me know!

Thanks in advance! :-)