Previously my Tecra laptop would not start up. A friend finally got it to boot by basically twisting the base of it over the corner of a table. Will now boot but randomly will lock up/freeze etc. Took it apart (luckily no parts leftover when put back together) and reseated all connectors. Same intermittent problem May be a cold solder joint but could not visually see any. There are 1000's of course. Has anybody seen a similar problem ? Would appreciate a direction to follow. I do get the bunch of horizontal and vertical lines on the display intermittently as well, especially if I press down hard on any key.