Alan,
You are reading the schematic correctly - yes there should be a
connection between the cathode of D10 and the anode of D9 (check to be
certain they are connected with an ohmmeter first).
If you find the path open, you could install a TEMPORARY jumper between
D10 cathode and D9 anode on top of the board to see if everything comes
back to life. If that restores full function, then remove the board to
find the damaged PC board trace or (more likely) the bad solder connection.
Nothing in your measurements indicate a bad diode to me. A diode
conducts positive voltage from the anode to the cathode (hint: follow
the arrowhead on the diode symbol), but blocks a positive voltage in the
opposite direction.
73,
Don W3FPR
Allan Bacon wrote:
I started tracing 13.8 V from the power source
Input 13.8 V
Diode D10 Cathode 13.8 V Anode 0 to ground as per specifications
Diode D9 Anode 0 V Cathode 0 V
So, it seems power is not getting to the D9 Diode
From the schematic on page 64, it looks as those are the only components on
the trace from power injection to the KPA-100 to the "Aux 12V" at J4
Here is where my lack of knowledge shows up -
1. Since voltage is not present on either side of the diode, should I pull
the heat sink and check the trace on the board?
2. Or - Does a bad (not even sure what that means) diode prevent voltage
from showing up?
3. Or - What
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