Well, If i put some pressure at the top edge of the memory board toward the analog board - it works (do not know for how long). I took some paper and pressed it between the board and the metal frame - this way I put some pressure at the lower third of the board towards the analog board - this worked for 1 hour and than the Classic crashed again. So everything looks like a bad solder point. But I still think the connector causes the problem.
Bye,
eweri