I had to spend the evening digging through everything again to convince myself that a hard drive problem isn't why I stopped the repair 16 years ago. (It went through an earthquake, & even though it was barely felt where I was, about 100 miles away, the utility power was messed up enough to kill the DC power-in module.)
Fun fact: When laptops were thick-as-textbooks monsters, some manufacturers broke up the motherboard into a mainboard with modules sandwiched above. Toshiba did that to my laptop: 3 layers of 4 or 5 modules stacked behind all the peripherals & keyboard.