6940 Printer problem

I just worked on a 6940 HP printer for about an hour replacing the color cartridge to try to get the left blinking tear drop blinking light to go away. I used three different cartridges but all still gave the same problem. HERE IS WHAT I FOUND: THERE IS A WIRE ARM THAT APPEARS TO HOLD IN THE CARTRIDGE IN PLACE. IF THE CARTRIDGE IS NOT PUT IN CORRECTLY, THE WIRE WILL SWING AND PUNCTURE THE CIRCUITRY AT THE REAR OF THE CARTRIDGE SLOT BREAKING THE CIRCUIT AND CAUSING THE INK CARTRIDGE INDICATOR ERROR LIGHT TO BLINK AND NOT TO BE RECOGNIZED. I HAVE TO BELIEVE THAT THIS IS A COMMON PROBLEM AND ONE THAT HP SHOULD HAVE CAUGHT IN THE DESIGN OF THE HP 6940 PRINTER. ONCE THE CIRCUIT IS PUNCTURED BY THIS WIRE AND BROKEN, IT CAN NOT BE FIXED WITHOUT REPLACING THE BAD PIECE OR MODULE. TO BEST SEE THE PUNCTURE, USE A FLASHLIGHT AND LOOK AT THE BACK OF THE CARTRIDGE SLOT LOOKING FOR A BREAK IN THE PRINTED CIRCUIT. GOOD LUCK!