MacBook A1278 crashing when board is bent

[RioRio]

I have an A1278 Mid 2010 that is crashing randomly. AHT finds no issues. But when I bend the Macbook a litte bit it crashes instantly. It either freezes or the screen turns one color, either blue or red or green. One time after this happened I got three beeps after restart. I removed the ram and put it back, then it worked again.
I guess there is a cold joint on the board. How can I find it?

 

[2informaticos]

Classic RAM slots failure.
Test each slot one by one.
If you find one good, max the RAM on it.

 

[RioRio]

Classic RAM slots failure.
Test each slot one by one.
If you find one good, max the RAM on it.

I have tried both ram slots separately with no success. As soon as I put a little bit of pressure on the topcase, the screen instantly turns blue and freezes. If I don't touch the macbook and run it with an external keyboard and mouse it runs for hours without problems. As soon as I move the laptop around it crashes.

 

[2informaticos]

Resolder RAM slots pins from the edges, may have luck.
Also try to block somehow the RAM modules, inserting something near their borders.

I'm sure you can find such board cheap on second-hand auction sites on Internet.
Don't waste to much time with it.

Please, write directly into reply box, instead of clicking Reply button.
I don't see any reason to quote an entire post, visible few centimeters above.

 

[RioRio]

Thank you, this was helpful! The board works now! I have noticed a tiny bit of corrosion where the Ram slot pins are connected to the board. I removed what I could with a metal tool and then I've put the board into an ultrasonic cleaner. Now the board works perfectly and does not crash when I bend the laptop.