Casio C-701 Fix attempt

   So I got a Casio C-701 on eBay in badly bused condition, I attached an image for you to see, window cracked, buttons missing, dirty, etc.

                       

   But I was hoping to find some decent parts inside, maybe even get it to work. After receiving it first I removed the module and disassembled the case (and I mean removed side pushers, keyboard crystal, etc). I managed to salvage and clean everything but the crystal and keyboard.

   Regarding the module I disassembled it and started to do a full diagnose. At first glance there was a lot of corrosion due to leaking batteries so I had to clean that up. What I was pleased with is that all the other parts on the module except the PCB were quite clean. After the PCB cleanup I started to check with a multimeter the traces that looked suspicious. Needless to say I found three in close proximity to the batteries that were broken. Usually it happens in this area as it is the most exposed to corrosion. 

   For the repair of the traces they had to be regenerated. Usually this can be done in severa ways (make bridges with wires, retrace them with a fine soldering iron, regenerate them with conductive silver). But I support the last solution, the first two could be clumsy on small traces and adding wires just adds thickness to the module and that usually leads to bad contacts when reassembling the watch as the parts do not come together properly. But regeneration o the traces requires a lot of work if you want to be neat and have a good result in the end. I recommend doing it only after you know exactly what to fix and that it will work after the fix.So just to see if only the traces are the fault I had to do a quick rewire. Below are some shots of the work done under the microscope.

    Needless to say after reassembly of the module and an AC reset the watch started showing the time (I do not have a shot unfortunately). I was pleased but some issues still existed: the watch was running too fast, and I could not cycle through the modes of the watch with the Mode button. The running too fast I suspect it has something to do with the adjustment potentiometer or with the small capacitor next to the crystal. One of them is faulty as no matter how I tried to adjust the potentiometer the watch ran the same.
   Now I took away the wires in preparation for the regeneration but I have to wait for some supplies in order to do the work.