remote control keypad conductivity repair

"Thomas Williams"

Conductive glues are rare animals for this reason.

Why don't YOU try it ??

.... Phil

I use conductive paste:

If available, I've also used Aquadag (water based graphite paste).

Before you attack, clean both the graphite button bottom and the gold contacts on the PCB with alcohol. It might just be grease on the contacts.

The problem with mixing your own conductive graphite concoction is that only a few formulations are actually conductive. If you don't add enough graphite, or the graphite particles are too small, they will not touch each other and therefore will not be conductive. I've tried to make my own conductive glue with powdered aluminum and epoxy. It failed badly and was mostly an insulator. I eventually got it to conduct by radically adjusting the aluminum to epoxy ratio, but with little epoxy to act as a binder, it was terminally brittle.

Anyway, try it. You might get lucky and find the right combination of grain size and graphite to glue ratio. Test with an ohms guesser. Your remote should work with anything less than about 1,000 ohms per square, but I'm guessing:

One more:

I haven't tried these but they sure look plausible.

I ran the abut in this problem a few years ago. Previously, disassembly and cleanout with detergent water worked to perk up a balking RC. But a few years later, that did not solve all dropouts. I took to scrubbing the little rubber conducting boots with lacquer thinner, but that still did not solve eve half the dropouts.

My last resort was to add an aluminum foil bits the size of the footprint to each contact. That perked up about half the dropouts, still not good enough for serious cassette and DVD watching where the program content was recorded off of standard broadcast with its weighty commercial content.

As a "last" resort (there is really always "just-one-more" to be found), I went to mother Radio Shack and bought a universal control. It included my VCR and TV codes, so now I'm back to 95% RC functioning (nothing's perfect).

Ange

Rob pairs (or more if same matrix dimensions) of buttons cut from the pad of some disused zapper that has much the same size and spacing of buttons.

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thanks, Jeff. your post was quite helpful (unlike some of the others here, I won't mention any names ("Phil, Jamie and Angelo" (at least the latter made an attempt)) will try the window defog preparation first, then later explore the two articles on making your own . . .

Y'er welcome. It's a common problem. Incidentally, if you're going to try making your own graphite conductive paste, don't get the bright idea of using graphite lock lube. To be a lube, the particles must be spherical, which will not touch each other, and therefore not conduct. What you want are graphite flakes, which will overlap, and therefore conduct. Good luck.

Source for guaranteed "flakey" graphite ?

The author of one of the links I previously mentioned uses AGS Extra Fine Graphite from:

I have a small 4 oz bottle of graphite in the office I got from an auto body shop. They use it for lubing window and lock mechanisms in the door. It seems like a lifetime supply.

Doing some more reading, it appears that only some lock lube uses spherical particles. Most of the cheap stuff is flake, so I guess it's probably acceptable to use.

Other sources:

More:

Spherical Graphite (used in lock lube and Li-Ion batteries:

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There is conductive paint for just this purpose at electronics stores. Ford Electronics in Fullerton, CA had some. I saw it there. I think they ship.

FWIW I tried the aluminum foil glued on, I didn't have 100% success. Since I wanted a 100% working remote control any less than 100% is failure. I haven't tried the paint.

Please note that the original question was about making his own formulation.

I call your missing link and raise you 4 more:

How about Aqua-dag? I wonder if it is still available? Used to apply a conductive coating inside and outside of CRT envelopes.

tm

Aqudag won't work, however the Chemtronics remote repair kit works great. Chuck

Here is the link to a product specifically made for fixing conductive keypads.

It works... I've used it.

keypads.http://www.mcmelectronics.com/product/CAIG-LABORATORIES-K-CK44-G-/200...

I tried it ( Caikote 44 ). It worked fine for a couple weeks, then several of the keys died. Disappointing.

keypads.http://www.mcmelectronics.com/product/CAIG-LABORATORIES-K-CK44-G-/200...

Try Neolube.