Re: Keypad problem ?
Czesc Dominik,toggle quoted messageShow quoted text
Jak sie masz?
Just as a side note on most "elastomer keypads" (like those on your TV
remote) in general.
I don't know if this is the same type as inside the AP keypad, though.
I have found that the rubber membrane on a "typical electronics product
keypad" leaches out some kind of oil as the years go by, probably more if the
push buttons are used very often, like "TV channel surfing". I suspect this is
the embedded "rubber mould, release agent", that remains behind in the rubber
during manufacture, and slowly comes to the surface. Surprisingly, the oil
film on the PCB, seemed about 1/16 inch thick! Quite a puddle, not just a
film. There is no way that the carbon bump under the rubber button could make
electrical contact with the etched copper pattern under it, through that much
oil. I have now repaired my old Jerrold TV remote keypad about 3 times, and a
few others for relatives, simply by taking the case apart, and washing both
the rubber sheet and the matching contacts on the circuit board. I just poured
the Palmolive soap on the PCB, dunked the circuit board in the sink, and
gently scrubbed off the oil in the mild sudsy dish washing soap (NOT dish
washer detergent). On one unit, I tried, (unsuccessfully), just spraying the
PCB with Windex, Isopropyl alcohol, or similar degreaser, but this scum
requires a bit of rubbing with a good soap to make the contacts work longer.
The keypad worked fine for another couple of years, or more, before my
favourite button (channel skip) leaked out more oil, and another washing.
By the way, the oil wasn't from kitchen cooking grease in the air, since
the TV remote pad was always in the living room, and certainly hand oils can't
leak through a full, solid rubber, sheet of buttons - so there seems to be no
external source of this thick oil cover, other than the rubber membrane
Mind you, such home remedies may be frowned upon by the manufacturer -
especially dunking the PCB in water - but since I was going to toss it away,
I took a chance and continue using my original controller for many years. The
water didn't affect the electronics after drying (isopropyl spray like
eyeglass cleaner, might be a good final cleanup of any possibly remaining
Home repair is better than recycling.
By the way - the AP Hand Pad has a 3 year warranty, so don't try the above
home remedy, until it has expired, and you aren't sending it in for
I'm curious, Dominik, when you took the AP keypad apart, how clean was the
PCB surface, and how old is your unit? I can't imagine why there was a "trace"
needing repair, or how it might have been damaged. That is a quality concern.
I wonder if the PCB can't take a lot of push button flexing, in the cold.
----- Original Message -----
From: "Dominik Wos" <firstname.lastname@example.org>
Sent: Tuesday, April 17, 2007 12:28 PM
Subject: [ap-gto] Re: Keypad problem ?