Erratic power short when KB/case touched
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Apple MacBook Pro "Core 2 Duo" 2.5 15" (08) Specs
Identifiers: Early 2008 - MB134LL/A - MacBookPro4,1 - A1260 - 2198
MBP15", silver KB. Been dropped a few times; only proximal results are a single green line on display and several dents in case. Warranty expired.
Gradually it began having a problem where, if touched "wrongly", it would suddenly power off completely. No warning, nothing, just total immediate power off.
This grew worse over time. There was no clear sensitive spot - could be somewhere on base, any place on KB, monitor tilt - pretty much anything MIGHT set it off. Being placed on a lap vs. desk seemed to improve this slightly.
Sudden poweroffs caused some s/w issues, e.g. preferences lost (presumably had been treated nonatomically and so got wiped along with RAM). Otherwise HD seemed fine. RAM test clean.
Case shake revealed no rattle. Systematic probing showed no consistently sensitive spot. Poweroff could occur anywhere from immediately after power on to several hours in use. System temperature had no effect, happened during cold boot too.
Popping top case revealed no obvious defects or shorts. Disconnecting HD, DVD, battery had no effect (except of course w/out HD boot would not progress past attempt to load OS). Same issue running from battery, plug, or both. Very light touch on any part of PCB could set it off... or not, no real consistency.
I've not been able to determine the root cause yet. Obviously an electrical short somewhere, but can't tell whether internal to PCB or maybe PCB touching e.g. some part of metal case in bad way. Haven't yet tried pulling PCB out of case.
1. What should I do next to diagnose/fix?
2. Guesstimate % chance of successful fix.
3. If dead, what's the best way to recover money from it on parts? E.g. can I give to someone (for a cut) to part it out for me? What parts are worth selling on ebay?
Obviously will dump & wipe the HD before doing so.
To clarify, you never get this prompt randomly, correct? This would rule out a faulty power button.. is there a dent on the top right side?
Have you tried to use a USB keyboard/mouse, or getting one of those incase plastic cases? And when you just don't touch it at all (USB kb/mouse) it won't restart, correct?