On 28/01/2014 20:29, Pat wrote:
I started using my old Sony STR-AV910 receiver after it had been
stored for a year or two. Everything worked except the remote. One
battery was in pretty good shape, but the other showed only 0.8 volts.
However, neither battery was leaking. I installed new batteries, but
still no output. I tried removing and reinstalling the batteries a
few times and finally gave up. (I did learn that, unlike my old
iPhone, my newer iPhone has an IR filter on its camera, though).

Anyway, I went to 800-remote's web site and saw I could buy a
refurbished unit. However, if the problem was caused by dried up
caps, a refurbished unit of the same age might fail soon. While
thinking about it, I noticed a "fix it yourself" link on their site. I
clicked on it and was instructed to remove the batteries, press every
button once, repeat for every setting of the two slide switched and
then reinsert the batteries. I was very skeptical, but sure enough,
it works fine now. I can only guess, it needed to be fully reset and
pressing the buttons fully shorted any charge remaining on high
impedance input lines of the ic. Any other thoughts on why that
procedure fixed it? They claim it fixes 1 in 3 failed remotes.

Pat


Probably insulating black CuS corrossion on the slide switches,
corrossion under a key would not stop the unit as a whole from
operating. Daily or regular use keeps that corrossion at bay,
by the wiping action of the phosphor bronze sliding contacts.
At least the corrossion product of silver plating is conductive and of
course gold plating does not corrode in normal circumstances.