C
Cursitor Doom
Guest
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....
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....