Here's some tech for you lot to get your brains around. Fixing my boys solar calculator that no longer powers up. I have successfully disassembled it and testing brings up a zero volt reading on the + line. Traced to a broken solder joint. Only problem is how do I solder such a small joint? I can only just see it with my old (and somewhat drunk) eyes. The screws that held the calculator together are so small i can only pick them up with a wet finger! The tip on my old soldering iron is about as big as the IC itself!
If your soldering iron has a replaceable tip, you can get a range of sizes. A magnifying glass on a stand helps. If you are soldering regularly, one of these is a good idea:
Just buy a Conductive Pen to repair the trace, Maplins do them. Cheaper to buy a new calculator, a quid. http://www.poundland.co.uk/scientific-calculator
How about making a fine tip for your soldering iron: http://www.instructables.com/id/Making-a-fine-tip-for-your-solding-iron-for-SMD-so/ Regards
I've done that before. But be warned. Start winding it all the way up round the tip screw. If you wind it just round the tip, when it heats up - it falls off! Mr. HandyAndy - Really
I used to solder such small PCB soldering points using a pointed soldering gun. I use Gooth soldering gun to fix such things,