5 specific keys sporadically not working - tilting helps

Hi,

my MacBook's keyboard is acting up. The "a", "q", "1" and "backspace" key as well as the left shift key sporadically don't work as in I can press the key but the system doesn't recognise them.

When I then tilt my laptop forward, they usually start working again. An Apple technician swapped the trackpad and the cable but that didn't help. He recommended exchanging the top part with the keyboard (as the main logic board is fine). My question is: Can I get around that? Does anybody have an idea what might be causing these specific problems? Or how I could fix them?

Regards

Justin