In part 1, I described how a defective Navionics CF chart had damaged the chart reader circuitry in a Raymarine C90W I was working on.
My initial thought was “I better throw this damn thing away before I screw up and accidentally put it into another machine and nuke its chart reader”. My hand was half way to the garbage can when I paused and thought – “Ah what the hell – take a look”.
I grabbed my knife and proceeded to gently pry open the case. I expected the case halves would be ultrasonically welded together, and was pleasantly surprised to see that it was a snap fit arrangement. Once the case was apart, the problem was glaringly obvious – AND repairable!
It didn’t occur to me at the time that this would make a good IRoD, so I didn’t get a photo showing the damage. Damn!
The cartridge has a circuit board and a small connector with 2 rows of pins. The edge of the board is fitted between the pin rows, and the pins are soldered to small pads on the boards edge.
Somehow, one of the connector pins had been forcibly pushed OUT of the plastic connector shell by a chart reader pin. The metal pin was now exposed and free to move and ultimately came in contact with the pins on either side of it – creating a short circuit.
This caused the chart reader power switch circuitry in the C90W to melt down.
The pin had an “arm” that protrudes out of the connector shell and is ultimately soldered to the pad on the circuit board. The arm had broken off, and could not make connection to the pad. I had to partially reinsert the pin then solder a VERY small wire to the end of the pin, then to the pad – thus replacing the missing arm and restoring its electrical connection to the appropriate pad on the circuit board.
This photo shows the pin – minus its arm – partially reinserted into the connector shell.
This photo shows a 30 gauge wire soldered to the pin and the pad.
After the wire was trimmed and the work area cleaned, I put the assembly back in the case and snapped it closed. I tested it on a unit I own (I wasn’t ABOUT to risk a customers unit!) and was happy to see that it worked perfectly!
“Some days you get the bear, some days the bear gets you”.
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