Step 4: Repair the Connections
Using LOW heat (you do not want to melt the ribbon or the solder on the board), slowly heat the ribbon cable where it is connected to the mainboard to soften the glue. At the same time, gently but firmly rub the connection strip with the pencil eraser.
1. Try to avoid directing too much hot air onto the LCD itself as this could damage it.
2. Apply enough heat to melt the glue holding the ribbon connection, but not enough to melt the cable itself.
3. If after the first try the problem is not resolved, try rubbing the connections down with something firmer. I repaired two identical phones using this method, and the second one required that I use the back of a plastic screwdriver to force down the connections.