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.