My trackpad was driving me up the wall, bouncing all over the place. Ifixit Trackpad comes with extra screws, hinge and adjuster. You won't believe how tiny these screws are! If one falls in the carpet-it's GONE! Bless you Ifixit! To center when re-installing adjust by sliding a thin piece of paper (scotch tape?), under bottom of trackpad, let Trackpad rest on it's own weight and then tighten one top and bottom screw a little bit, and eyeball it, just the tiniest crack of daylight on each side. I strongly suggest the highest quality magnetic screwdriver you can find. The little torx screw disc is an adjuster. If too tight, trackpad won't 'click.' On a Mac, click is not really essential as long as tap and slide are working right. Needs a small amount of clearance. When properly installed you can 'feel' the click if it's right. Probably won't need to mess with it at all. Now my trackpad works like it should, I am a happy camper!

I was using my Laptop (literally in my lap), with the charger connected when it felt very warm on my pant leg. Felt the bottom of the case by the Mag Safe connector and it was very hot, almost burnt my hand. Surprisingly hot. Wouldn't charge right after that, kept getting hot, intermittent charging. Looked at the contacts with a jewelers loupe; the gold contacts were burnt and blistered, plastic melted so it wouldn't make full contact with the AC charger. Charger contacts OK. Replaced DC in board, works like new, saved a bundle of cash. Laid all the screws out in related groups on table top. e.g. All 10 cover screws in a square. MoBo Screws in MoBo pattern, or, you could use a small metric/millimeter ruler to tell which screw goes where.