So when my Mom was talking with the principal and gifted teacher about how I'm gonna do school this year, she brought up the idea I had to have them send me their broken graphing calculators so I can see if I can send any back working. They loved the idea. The icing on the cake: I'm gonna earn credits for this as a gifted project, AND I can record my findings and present them as my senior project(maybe with your help I can find clues to how the calcs are most commonly abused and broken). Obviously I'll be relying heavily on the people and resources of this forum, without which I would likely be pretty helpless. However, I figure if I consult with you guys regularly, I can learn a lot, maybe have some fun, and earn credits in the process.

I'm extremely jealous. What kind of brokeness will you be trying to fix, though? You may have to end up shipping a bunch of these to me for some fine-grained soldering.

Since it's from a school, I'm going to assume broken screens, missing/broken keys and perhaps some internal issues - such that would require soldering.

The most frequent thing that seems to "break" in these is the problem where the screen will power on and off, but only display a blank LCD. You can only see any sign of life from the slight darkening of the display when power is initially applied. Over the many years I have seen this I have always assume it's a failure of the LCD's controller IC, but it just occurred to me yesterday that an open circuit in the parallel data lines to the LCD could cause similar symptoms. I'm going to experiment with one of my many broken calculators and a multimeter this evening and see what I can find.

That's usually been the case in my experience.

Missing keys are trivial. As far as sticky keys because of user failure (spilled soda/coffee, etc), just disassemble the calc and soak the front case and the keys in isopropyl alcohol (H2O2, aka hydrogen peroxide aka rubbing alcohol). Oh, make sure you have a small Phillips screwdriver and especially a Torx-6 screwdriver.

My Dad is one of the few people I know who actually has a set of torx screwdrivers...

Good, then you're set in that department. How handy are you with Helping Hands, 30 AWG wire-wrap wire, and a fine-tipped soldering iron?

Wire-wrapped wire is what coaxial cable uses, correct? If so I understand how that works quite well, if at a much larger scale than in a calculator. I also used to play around with small wires and batteries and junk when I was ten. As for soldering, my dad showed me how a few times, and I can always practice with smaller less complicated projects before doing anything with a calc. Then again, we're talking about calcs they were gonna throw out anyway, so nothing's really at stake if I mess up.

Oh, now you DEFINITELY need to ship me some of those. No, wire-wrap wire is about 1/16" thick; the conductor inside is about 1/40" in diameter.

Oh I've worked with that before. I used it in building small LED timers back in 5th grade. The whole point of this is for me to learn and better myself; sending you the calcs would cheat me of that. I'd benefit a lot more from mentoring and perhaps Skype sessions.

Make sure you get a decent set of wire strippers if you intend to use narrow gauge wire. I'd personally consider desoldering tools - namely a desoldering pump ("solder sucker") and braid - just as important as soldering tools for repair work. A fine-tipped iron is useful, too, but fine solder is just as important.

A logic probe and a multimeter with a continuity tester are also invaluable tools.

I found a desoldering pump obnoxious to work with, and much preferred the braid. As Kerm said, a helping hands is invaluable. I would get something with many hands, and as many joints as possible. And a nice magnifying glass. One of my worst soldering experiences was when I had a sub-par helping hands that couldn't move much, and I had to hold one part instead of just having the helping hands do it, and I burned myself pretty intensely. I've still got a scar from that one.

I use both; the desoldering pump removes most of the solder, and the braid wicks up the rest.
I use a lamp with a magnifying glass built in, like this. I find it gets in the way less than the magnifier on a set of helping hands.

Oh, that looks quite nice. That seems like a better way to go.

Funnily enough, I've found the opposite to be true. I am incompetent with the braid, but the desoldering pump works well for me.

I can never manage to get it to actually suck up the solder! Maybe I was always doing it wrong. You will have to show me the right way.

Check that the inside of the desoldering pump is clean; they do eventually get clogged up with solder, which will prevent the spring from moving fast enough to create a good strong "suck".

They also work best if there's a big blob of solder to remove. Adding more solder to the joint first may help.

I have wire strippers, with a built in current tester, and I'm sure my dad's skunkworks has some helping-hands, lights, and whatever else I'd need for minor repairs. Though I will likely be asking for help and guidance from you guys a lot.

Well I'd certainly be happy to help, though a little less qualified than Ben or Kerm.