Wednesday, March 31, 2010

j!


I spent $7.50 and ordered the new chip.  But I didn't want to give up just yet.  Someone in RGP said you'd be surprised at what would cause a signal from the chip to go funny.

You may remember that my batteries came corroded and the main board looked like this.


When I cleaned it, I was really too easy on it.  I lightly brushed it until it looked OK.  But there was just too much of a connection between the "j" being one of the corroded traces and the "j" being the segment that wasn't working.

I tested some sanding and cleaning techniques on a piece of junk board so I could get a feel for how rough you can be on a board before you break a trace, and it turns out that they can be pretty tough.  I then cleaned the system board more agressively.

I used a scotch bright pad, the one that's plastic, but equavalent to a 000 steel wool.  (Don't use steel wool!  You don't want conducting junk flaking off  all over your board!)  I used it and cleaned the small section of board.  I then used a magnifying lense and a dental pick to make certain there was nothing between the traces.

When I fired up the machine, the "j" segment worked!  However, I've decided that the corrosion really needs to be cleaned up, so I'll still be removing the two chips, cleaning the area thoroughly with vinegar, cleaning it  with the scotch bright pad, and then finally soldering in some sockets and replacing the chips.

Here is what it looks like now:

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