Bizarre (?) Electronics Problem...

[mayhem]

I’m more than a little embarassed to report that an oversight (on my part) in the realm of ‘idiotic’ has now been addressed and the spare receiver is working again.

Tape monitor left on or mute?

 

[Peter B.]

Load in Hebbin... this has been a strange sequence. It got even stranger today.

I'm loath to reveal my idiocy, but here you go. The speaker I used to test the spare receiver has screw terminals... slip the lead through the drilled post and tighten the nut. Evidently, I caught the insulation rather than the wire when I first tested.

As I suggested in my last, with the spare receiver working properly, the 'dimensions' of the mystery were reduced substantially. One failed receiver, no more no less.

This noon, I took the ailing (recently-in-use) receiver off the shelf where it resides, and put the spare one in its place. I hooked up the main speakers and checked radio function, then thinking there was some remote possibility a short in one of the input leads might be revealed, I left the radio playing as I plugged in all the source and monitor devices. No problems encountered.

I then popped the cover on the ailing receiver and checked the fuses. They were all fine.

I then retested the receiver. It worked fine.

I then scratched my head...

At this point I have absolutely NO idea whatever why the one receiver 'balked' as it did... for over a week... despite 'creative' prodding from me.

It sits across the table from me now, silently smirking.

Not that I haven't been 'bested' by inanimate objects in my past, but this one will be remembered for a while.

Peter B.

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[WhitePine]

Could be thermal expansion and contraction. When you take the cover off of a piece of equipment, it cools somewhat. Sometimes this is enough to bring the device back to life. Usually, it something barely making contact that finally gives up the ghost and causes the initial failure. When you take the cover off, the cooling effect causes just enough movement that contact is restored and the damn thing starts working. Usually, if that happens it will fail again in the near future.

 

[mayhem]

Could have somehow shorted one pair of speaker wires maybe. Every time you turned it on the receiver went into protection mode the instant it kicked the power to the speaker terminals on...the breaker for this will reset itself when you cycle power, but so long as that short is there it'll keep going into protection mode every time you fire it up. Just a guess.

 

[kettensäge]

Our stereo does the same thing, one or both speakers randomly cutting out. I have narrowed it down to an internal connection near where the speaker wires attach. If I go back there and just touch the wire and lever type connector, speaker starts playing again, sometimes for a minute, sometimes for a month.

 

[Peter B.]

WhitePine & mayhem:

Points taken, but...

The original problem first manifested trying to turn on a cold machine... which subsequently never got warmed up again... and then 'repaired itself' cold as well.

Though (in my relative ignorance) I suspected the protection circuit might be involved, I _don't_ think the speaker wires got shorted... where the receiver is, there's nothing to disturb them. And the light for the circuit continued to go out shortly after startup.

I think it will remain a mystery unless/until the spare receiver (now in use) gives problems and I'm forced to have one of the two repaired. At this point, I don't know of a ready way to invoke the problem again in order to (try to) diagnose it. If I did, I'm the sort who would 'pursue' it. I've solved a number of problems through the years by following hunches and sheer persistence.

But for the moment, I'm going to leave this one alone.

Thanks again for all the help.

Peter B.

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[pyper]

Maybe the volume control.

I have one that will work fine for a while. Then no sound. Whack the knob with something and it works again.