Answer to: Access ok but won't clickSounds like you need a new trackpad, there is a replacement guide on ifixit. They have a tendency to stop clicking but continue to register movement.
Answer to: MacBook Pro not showing login, just white screen, cable loose?Hi Sounds like a hard drive connection issue. In my experience Apple products are very sensitive. What did you use to clean the Mac? I would make sure that all the connections are secure and that your HDD cable is not damaged. If none of that works try an SMC reset.