As you probably know kicking, banging or moving a hard drive could easily damage the platters if reading or writing, obviously you'll have looked for dry joints. What about checking the clocking oscillators, sometimes vias, those plated through holes can they give that kind of trouble along with earthed lugs on metal screens such as tuner modules, the screening forming a bridge to a different area of the pcb for example.
Just trying to stoke some ideas, that's all!
Dave
