Transformer shot! (was scope SMPS/ capacitor venting)
On Sat, 20 Feb 2016 12:55:19 -0000 (UTC), Cursitor Doom
wrote:
On Sat, 20 Feb 2016 01:14:09 -0500, legg wrote:
Recheck pin function before jumping to conclusions.
Right; now re-checked. DC measurments proved (unsurprisingly) too close
together so I re-tested using 100khz instead. These are the impedances WRT
ground of the output taps of the long winding in the order they actually
come out of the transformer:
GND, 0.17ohms, 0.17ohms, 0.26ohms, 0.28ohms, 3.7ohms, 3.8ohms.
So this doesn't seem to tally up with the schematic. Or does it? I need a
pint of strong coffee to kick-start my head on this one. :-/
Anyway, later...
If the transformer is removed from the board, which seems to be the
case, you can probe the PCB for continuity between known component
leads/schematic nodes and empty PCB transformer pin lands.
Using a logical physical numbering scheme (if one is not allready
present on the actual transformer body), you can assign numbers to the
board and the schematic, for reference.
RL
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