Hmmm... installation failed. Looks like you might need to pay for it to be able to actually alter the voltage. I've looked, but can't really see what the disadvantage over undervolting is (aside from overdoing it, of course). Is there something I'm missing?
The more I look into it, the more I'm realizing that this is getting to be a real undertaking. Kind of revel in the idea of fixing this thing (especially because the current 15" MBP is out of my price range, new specs notwithstanding), but it's starting to get complicated:
So far:
Remove busted superdrive (win)
New battery: $30 (apparent fail)
Up next:
Used, undented bottom pan: $40
Thermal paste: $5
Requisite tools: $10
In the pipeline (would be nice but not necessary):
New 7200RPM 500GB HD: $60 for a highly rated one on Amazon
Nuther 7200 RPM HD to fit in the optical drive + necessary adapter = ~$80
Copy of Snow Leopard: $30
Lion: Another $30
New screen: $130
Total cost: $415
Labor = highly intensive
My expertise = marginal
My love of fixing stuff = prodigious
Result = ???
Worth it = ???
Haha, you have quite the project ahead of you. I think it is though, as you have a working computer, you just have a problem with heat. But lets all pick this apart to streamline the process.
You have a new battery and you, to get this straight, did NOT get the heating when using the machine, WHILE watching videos, withOUT the battery correct? Of course, this does not rule out the battery, but it does mean something if this is true.
I would say to get the thermal paste and the tools first, as the bottom of the computer is, although important, not as important as fixing the actual internal problem. You can take the entire bottom piece off and hold it up on legos and the machine would work, in theory of course.
Get the thermal paste, the tools, and read guides to the T so to ensure you get that right. If al goes well, you should fix the problem.
The machine itself is a good machine, so after fixing heat and the body, you could definitely get some new hard drives. Do you feel the one you have now is failing? Also, do you have a hard drive for time machine?
If yes to the first and no to having a TC, definitely get an external for the TC and THEN put money aside for the drive (maybe half or something, keep a piggy bank or whatever) WHEN that drive fails. The TC works as a safety net; if my machine breaks and I HAVE to use it, I can simply run to best buy, pick up the cheapest HD, and be back up the same day.
THEN I can send it in to apple to get it replaced with Apple care, but seeing as you don't have that option, the TM and money on the side for the HD when you need it is the best option, if you can afford to just run and grab it when you need it.
Having one on hand would be best (or replacing with new), but you can only gain in savings/capacity by waiting and getting when you need, at the expense of having the possible downtime.
Definitely get SL disks; you'll need them if the HD does die and you have to start over. Lion is great as well; I don't think that it's quite "ready" yet though; depending on how you use the machine, there are a lot of pesky little things that are occuring that people don't like. Of course, that's all subjective, but worth mulling over before you devote 30 bucks.
I have a free dl of it (already have it) but I'm still on SL with my 2011 MBP. I love Expose/Spaces and I could not imagine ever using the Cluster**** that is MissionControl. TERRIBLE.
And finally, screen as in, an external or the monitor itself?
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THere is no downside of undervolting. It's like drafting in a car (I thought of this analogy after I read your last comment and went to go bake chicken lol)
Drafting is great. Save gas, and you can coast to your destination. Downsides? Dangerous. You can hit the car in front of you.
With computers: Save battery life/less heat. Less energy is sent to the processor. Downsides? Computer freezing if too little current is sent when it's needed. Not too "bad" as you won't damage the system or lose anything, but if you're working on something and you don't save, you'll lose that file along with the time it takes to restart (and frustration).
All in all, I think it's worth it. I did it with my phone to squeeze out extra mhz AND save battery life, which is all good when you heavily use a smart phone all day. It locked up maybe... 5 or so times in a length of months? And I never turned my phone off.
Of course, that's a lot less damaging if it does shut off, but something to think about as well. Read up on other's experiences to see if it's worth it for you.
Hope this helped