I recently went to a second hand selling site named... well it does not matter. A seller had a CFX-9850GC PLUS along with a TI-83 cheaply.
The TI had some keys not working, almost easily fixable.
While the CFX-9850.... Well done CASIO.. There is no protection between the 4x AAA batteries and the PCB, just the PCB green coating... which led the calculator inusable. I had to use some sandpaper to sand down the corrosion.... Then I saw that the keys were working.
I knew the Casio had some Self-Test thing, which is F6 + a b/c + AC and I could test all the keys.
Then I used some nail polish to seal the sanded PCB area around the batteries power input terminals. The calc smells nice now....
Now at least if the batteries leak again, the nail polish should prevent the leaked battery juice from making damages.
My humble option is that the screen kinda sucks, too dark for me. My eyes are not what used to be.
My questions are....
I want to make an homemade cable-to-pc cable. Where do I find information to make one? I read I could connect the terminals of the 2.5mm directly to the RX/TX/Ground but I need graphical schematic wiring.
What tool I need to use to capture the screen?