T&L Publications

Hi all.
Fixed several remote controls for TV, DVD... typical household items.
Found mostly poor button contact from wear and contamination* , the 'pencil treatment' and cleaning restores functionality... for a while.

*The contamination I came across several times is in form of an oily layer everywhere inside the remotes; from unknown source. Perhaps emanating from hands ¿?
Until I found my own with such oily fluid in it. Solved the failure obviously washing it, but has never failed again in 3 years :
I keep/use the remotes inside its own longish narrowish shipping plastic bag, closed with adhesive tape to keep it from whatever causes such fluid intrusion/formation. Work just fine as new, for a looong time.
Miguel

I've found that "oil" inside them also, and don't know what to make of it. I really can't believe that it comes as body oils -- my hands are always dry and calloused and I don't rub my forehead with the remote, which would flood the poor thing. I tend to clean the button surfaces and the PCB contacts with IPA using a cotton swab and it fixes them for quite a while. I seem to remember reading about a contact "ointment" of sorts available from one or more electronic supply houses that you apply to those elastomer-like switch contacts/pads, but I can't remember which company. I wonder if DeOxit would work on those contacts without really screwing things up.

My current dilemma is with several really nice scientific calculators that have been in storage for several years that have developed non-responsive keyboards. They're nice calculators that either have really large keyboards (Sharp) or scientific/engineering/Greek notation (Casio) or decimal-binary-octal-hexadecimal conversion (all of 'em). They all have their fabulous uses, but you can't buy any like them these days without getting into huge 20-line graphing screens or $100 price tags.

I have had that phenomenon happen more times than I'd like to remember. I think its a chemical change in the molecular structure perhaps speeded up by heat and humidity. One thing seems certain - its a "Death Knell" that eventually kills it even if you perform temporary maintenance on it. The only good thing here is that by the time they crap out, the equipment is obsolete or at least by todays standards.

Correct.
Unexplainable origin of such fluid.
From a couple of years ago back, any and all new remote control I use, from day one lives inside its supplied packing bag, with adhesive tape securing it. It does not impair the IR beam.
Remotes of similar age kept in the same room with little handling/use do not develop that 'oil' . Has to be the hands...

A trick learned about carbon coated elastomeric buttons worn beyond reactivation with graphite, for remotes, calculators of ill keyboards:
Use a hole punch on aluminium foil and lightly superglue it to the worn plunger. Metal contact instead of carbon coated crap. Works !

Miguel

something that works better than the superglue is a elastic kind of glue..
super glue is brittle,and will not last long with a flexible button.

I think this was discussed some time ago and I remember that the oil was supposed to a breakdown of the silicone that is used to make the key sheet. Seems that it, like mother nature, wants to reclaim itself and return to it's primitive state.

Posssibly the heat from handling helps the process but I have also seen drive belts and rollers turn to goo while in storage. I don't think anything is getting inside because usually the top of the keysheet is oil free. Oddly enough, it is just the bottom next to the circuit board so maybe it's an interaction between the keysheet and board materials? Of course, because the oil is an insulator the keys malfunction.

I usually just disassemble and clean the board and keysheet with with alcohol, and use gentle cotton swab to wash the conductive rubber pads. Everything works well for a few years then it's time for an oil change again!

Len

my ancient cordless phone is the same way.. usually i have to take the pad out,.,wash it with DAWN, dry it and then put it back together..works again for bout 6 months.