Re: Puzzling IR remote control problem

ian field wrote:
"NeverExpectPowerAlways" <don't_even_ask@xxxxxxxxx> wrote in message news:yEgGh.5271$P47.2548@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
PeterD wrote:
On Sat, 03 Mar 2007 03:38:22 GMT, NeverExpectPowerAlways
<don't_even_ask@xxxxxxxxx> wrote:


If you have read this far and think you may have some insight, please feel free to post it as a reply to the news group.
Suggestions like: if you don't know what you are doing, don't try to
fix it?
Yeah, let's all never learn anything new.

Would that have been your advise to Tesla or Edison?

Let's all just get warm around the lightning fire until it burns out.

The symptom does have some similarities to an electrolytic with ESR issues, if you are going to get into fault finding you really do need to invest in an ESR meter such as the *** Smith ESR meter, changing caps in a random manner is more likely to result in damage to PCB tracks or solder bridges which would certainly make the fault become permanent.

Thanks, ian

There WAS a damaged track on the board. I say this because the signal voltage between ground and the track that connected the IR receiver to the 42 pin IC fluctuated erratically between 2 and 4 volts when the unit was plugged in but not powered on. I thought that I had located the problem on the track and made a careful repair, but the erratic voltage remained. Just this morning I severed the track at both ends and used an insulated wire to reconnect. The voltage is now rock solid. The track was not being used for any other purpose but to connect the signal from the IR receiving module to the IC that apparently controls the switches for the various functions that the remote is supposed to control.

I just measured the signal voltage and it measures +3.7 volts to ground with an analog meter and +4.75 to ground with a digital meter. I don't understand that. In addition to the signal line, the IR receiver module has a +5 volt line and a ground line running to it. The +5 volt line measures +5 volts with both meters.

The unit is still not responding to the remote, however, and I am off to radio Shack to buy another $4 IR receiver module to see if that revives it again. Perhaps the first one was damaged by the faulty track or it was just a faulty unit. The fact that it worked when first installed is heartening. It would seem to indicate that the 42 pin IC is not at fault.

Thanks again,
Jack
.

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