gotta start somewhere
Noticed on my Lifetime ultra that any transponders that had vertical polarization where no longer working on any of my dishes.
After extensive testing, I found my lifetime ultra was putting out:
22 volts for Horizontal (Should be 18 I believe)
16 Volts for Vertical (Should be 13 I believe)
Way out of spec! Is there a transistor in this box I can simply replace to fix the problem? I'm pretty handy with a soldering iron.
I think your original diagnosis is correct:
hardware failure.
And of course, the reason all Vert transponders are "missing" , is because you are getting horizontal signals when expecting vertical ones.
One of the more common failures in hardware this last decade, is leaking electrolytic capacitors.
However, this particular symptom does not fit that scenario.
Possibly, a semiconductor (transistor, zener diode, etc.) has failed or is failing.
You would not expect that sort of thing, unless it were over-stressed, either continually or due to a design or production flaw.
I suppose operating into a shorted cable might bring on a transistor failure...
Next up on the suspect list, would be a resistor.
It may have been a wrong initial value (production or design flaw).
Or, it may have been stressed (same as above), and overheated or burned.
You could open the unit and take a very close look at all the parts for anything that appears discolored.
And of course, a big brown/black char mark on the board would be a clue.
These are just the basic first-level trouble shooting points.
It could well be something totally out of the ordinary ....
.... like a corroded spot on your board from spilling lemonade on it.
edit: here's a thought.
Put your DVM on the AC scale, and measure those LNB voltages again.
Should be pretty much zero.
While I won't recommend you taking DC power readings inside the operating unit ...
... if you -do-, list those as well as any AC your DVM might register.
If you have one, use an oscilloscope and look for residual hum or noise on the DC power & LNB.