Originally Posted by brogers
For those with worn buttons that require stabbing with long slender fingernails to get any sort of response you can buy a keypad repair kit. I think anything with a conductive ink or paint would work. My remote is back and recognizes the slightest touch of the buttons. Not sure how long the fix will last, but I figured it is worth a shot before buying a new remote.
Okay, so I bought the CaliKote and I have my Harmony 720 apart. Call me an idiot, but I'm at a loss for where to go from here.
I see two kinds of contacts. The black buttons on the remote (numbers 0-9, "Guide", "Info", "Menu", "Exit", etc.) appear to have a conductive surface on the bottom of the rubber button that, when depressed, comes in contact with and bridges two wires on the PCB to complete the circuit. I would think that cleaning the bottom of the rubber button then using the conductive paint from the repair kit to replace that conductive surface would rejuvenate those buttons. Unfortunately, those aren't the buttons I'm having trouble with!
My problem buttons are the hard plastic silver ones--primarily the six programmable buttons on either side of the color LCD screen, but sometimes the D-pad in the middle of the remote too. It looks to me like these buttons have a non-conductive rubber "dot" on the back side that normally rests lightly atop a silvered mylar "dome" on the PCB. When the plastic button is pushed, the rubber "dot" pushes down on the mylar dome and causes it to deflect inward, where it presumably makes contact with a second silvered pad below to complete the circuit. These "domed" pads have some adhesive tape near them whose purpose seems to be to seal the edges of the PCB, perhaps to prevent contamination from getting under the dome, which might in turn prevent solid electrical contact between the dome and the pad below. (The adhesive has come loose, so that might be why I'm having problems!)
I *think* I need to remove the adhesive and gently separate the PCB layers to get under the "domes" and clean out any contamination. I don't think the CaiKote is going to help me much with those buttons (unless I find the silver surface has been abraded away or something).
Can anyone tell me if I'm on the right track? If I'm not, could you point me in the right direction?
I'm hesitant to just start trying to peel back this thin, delicate mylar layer without knowing for sure that's the right thing to do!