Robert,
What firmware were you operating with when it failed?
Was it the latest firmware?
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From my previous post in this thread:
The QMX+ assembly manual says D109 is a 3.6V 500mW SOD-123?
One such part is this from Mouser?
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So you want a 3.6 Volt zener good for 500 mW dissipation in an SOD-123 package.
I believe that Mouser part is a reasonable choice.
?
Use two soldering irons when extracting that part.
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Jerry, KE7ER
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On Sun, Oct 20, 2024 at 09:02 AM, Robert AD6XJ wrote:
My D109 is conducting both directions in situ. D106 & D107 conduct one way and briefly the opposite due, presumably, to C107 & C106 respectively (they are cross enumerated) charging.
Zeners still make my head scratch-- they act like "normal" diodes when forward biased and when reversed biased until the rated voltage then they also conduct reverse? ?At the knee?
Any way I only need a part number to get this QMX+ going, not a complete understanding of how the magic midget squirrels inside stack and load the electrons from one end to the other.
That is a VERY tight spot between its two bigger brothers!
Smiling,
Robert AD6XJ
