How to fix a "camera error" on my camera?

How to fix a "camera error" on my camera?

I send my Sony @57 in the repair but they said its working fine but now the camera error is keep on coming back. It seems like there are some connections that is loose on it because every time the camera error appears the other buttons wont work then if you press it a couple of times the camera is making a wired sound then the lcd will appear.