From: cd@notformail.com   
      
   On Sat, 12 Aug 2023 21:03:18 +0100, liz@poppyrecords.invalid.invalid   
   (Liz Tuddenham) wrote:   
      
   >Cursitor Doom  wrote:   
   >   
   >> Gentlemen,   
   >>   
   >> Whilst trying to discover why there was no audio output from a 4W amp   
   >> board, I noticed there was only 0.6V on the supply pin of the audio   
   >> output IC concerned. There should have been 13.6V. This pin was fed   
   >> via a 1 ohm 1/4W resistor. DC voltage measurements showed there was   
   >> 13.6V on one side of this resistor and 0.6V on the other! Clearly   
   >> something amiss here,  I thought. So it must have gone open circuit.   
   >> However, there's not the slghtest sign of any phsyical damage even   
   >> under high magnification, whatsoever to it: none at all. Prior   
   >> experience has always taught me such resistors burn out in an obvious   
   >> way which is dead easy to spot. Not this one. I'm just wondering how   
   >> unusual this is and if anyone else has encountered such an issue with   
   >> a resistor. Here's a photo. The resistor in question is the one right   
   >> next to the largest electrolytic. There it is, looking all innocent   
   >> like butter wouldn't melt, yet it's caused me a massively   
   >> disproportionate amount of head-scratching, the little shit.   
   >>   
   >> https://disk.yandex.com/i/dE9o0lh937qdrg   
   >>   
   >> When I get that out of circuit.... just you wait....   
   >   
   >Micro crack in the solder?   
      
   It'd have to be a pico crack given the hi-mag examination I gave it   
   and found nothing suspicious.   
      
   --- SoupGate-Win32 v1.05   
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