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Contributed by Puddledud.
Yesterday I settled to trying to get an analogue
multimeter that I had lying
about the place working. After testing it to find 'da nada' I pulled it
apart. The obvious problem
to be found were three fried resistors - goodness knows what else there
may be - and I set to
to replace them.
'interesting?' part of the exercise was that I took photographs and
then looked at
enlargements on the computer where I was able to call up pictures of
the colour codes on the
net and so try to identify the value of the damaged resistors.
Looking at the picture there are two resistors near a piece of black
shield - these
number 1 and 2. There are also two resistors directly underneath a
cutout hole in the board -
the damaged one of this pair is 3.
grey, grey, gold, red viz - 8,8 X0.1, 2% to give 8.8 ohms. This one
still worked and
registered 8.9 ohms when tested.
white, blue, ?? , red viz 9,6,X??,2% - this one is thought to match the
above the one labelled 3 and to be of 960 ohms or there abouts. The
resistor above the one marked
3 actually tested at 967 ohms.
violet, black, silver, violet viz 4,0,X0.01, 0.1% to give 0.4 ohms
I desoldered the resistors one just fell apart, one was still reporting
that had been calculated and a third - lying near to one of the damaged
resistors - had
enough markings in common with the one which fell apart that it was
possible to make a
reasonably reliable conjecture that it had been of the same value -
based on the tendency of
circuit designers to reuse values wherever possible.
A section of the photograph of the board, showing the burned resistors
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