A70: Before I jump in and disassemble

I have a Toshiba A70 notebook that I inherited which seems to be having an odd problem. The issue seems to be some kind of loose connection or shorting.
It seems that randomly, when I move the notebook, it will shut down (actually it doesn't shut down, rather it locks up completely, screen generally goes dark, but fans etc continue to run). Its not overheating as it seems to only happen when I pick the laptop up, or put it down again, particularly on a hard surface (mostly when I put it down on a table, rather than pick it up and run it on my lap). Also I can immediately fire it up again, and run for days without it locking up if I don't move it.

I've been thinking about disassembling for some time now, and I came across this forum (and the excellent disassembly instructions in the pinned thread). I wondered if anyone had been having similar issues.

 

Was reading some old posts about "Top Cover Modifications" to the A70 to prevent shorting. Anyone know when these were done, or how to tell (without completely disassembling) if mine has them already done or not? The symptoms seem similar, I'll see if the condition occurs more readily when I'm touching the speakers on the top.