Screen only works when mainboard is bent


I’ve adopted a devterm from a friend who hasn’t been able to get it working, and I’ve narrowed down the problem to a hardware fault.

I’m able to successfully get the screen to display properly when I bend the entire plastic assembly with only the mainboard & screen attached in a certain way. I’ve narrowed this down to bending the mainboard slightly, but when I secure it back in to the enclosure it gets positioned back so that the screen doesn’t work.

It also makes a whining when the screen isn’t working, and doesn’t when the screen is working.

Any ideas? I suspect it’s a cracked solder joint but don’t really have the tools to debug right now.