On Mon, Aug 20, 2012 at 3:12 AM, Tom Metro <[email protected]> wrote:
> > If you're curious, you can see a picture of the type of remotes in > question and the device they control here: > http://mvpmc.wikispaces.com/Mediamvp You are still using a MediaMVP? Is that paired with PVR-150s as well? > > My IR testing has been to observe the IR activity light on the device > being controlled. I have no reason to question this, though I ought to > take a look at the output of these remotes through a video camera to see > if they are perhaps producing a signal that the receiver is completely > rejecting. A regular digital camera will work for this as well. I'm actually using the same kind of remote as well (tand have noticed some corrosion of the battery > > Like most modern IR remotes, it's a really simple design: a 33 uF > electrolytic cap filtering power, a 24-pin fine pitch DIP surface mount > micro (no part numbers I recognize), crystal, few resistors, a few > transistors (appear to be used to multiplex the keyboard), an IR LED, > and a driver transistor. > > It's a single sided board with the only through-hole components being > the cap, crystal, LED, and the battery contacts. The cap and crystal are > close enough to the battery compartment that they could have been > exposed to some moisture and compressed air, but I can't see that > killing them. I know cap isn't shorted, and if it failed open, the > remote would still work, but would have reduced range due to starving > for current...or it might have a truncated pulse train if the current > spike causes a "brown out" for the micro. Viewing the output on a video > camera might shed some light on that. > > Short of probing things with a scope (checking that the oscillator is > running, etc.), I'm not sure what else to do. > > (On a side note, I noticed the silicone keyboard has a sticky residue > all over the surface that contacts the PCB (and on the PCB), which I've > found when disassembling pretty much any IR remote that's more than 3 or > 4 years old. No, soda or other liquids haven't been spilled into it. It > seems like the silicone naturally degrades in this manner. And yet it's > always on the surface touching the PCB, as if something in the PCB > coating causes it. I've tried researching this phenomenon online in the > past and found nothing useful...other than products for repairing the > carbon pads on silicon membranes. I'd sure like to understand why/how.) > > -Tom > _______________________________________________ > Hardwarehacking mailing list > [email protected] > http://lists.blu.org/mailman/listinfo/hardwarehacking _______________________________________________ Hardwarehacking mailing list [email protected] http://lists.blu.org/mailman/listinfo/hardwarehacking
