Hi, I had the same issue with the screen freezing and not turning on. After trying all of the above to no avail eventually I closed it and gave the system a gentle few bumps and shakes. Once doing this I found the problems disappeared and the system began working like a charm. I figured that there must have been dust or foreign material inside causing a short somewhere. After shaking it around it would seem I've dislodged the foreign material and eliminated the short. That's all I can put it down to. If anything was loose before shaking it wouldn't have fixed it. Hope this helps.