GEOSATpro microHD: No LNB Voltage Output

[cyberham]

My problem symptom is simple. I have no LNB output voltage from this microHD. I have proved the receiver works fine if voltage is available to supply to the LNB. To do this test, I connected my Openbox S9 and used its loop through connector to connect the microHD. The microHD then works fine on the polarity selected by the S9.

My question: Does anybody know if there is an obvious voltage regulator chip in the microHD that could be changed to maybe fix this? There are no visually damaged components inside that are obvious such as blown electrolytic capacitors. But if I only needed to change something like a chip to fix then I would try. Even with surface mount chips which I wouldn't normally touch, I have nothing to lose as the receiver won't work as is. And, for nostalgia since it was my first good receiver, I'd like to get it working.

Does anybody have a schematic for this microHD? Or even an old discarded microHD not wanted from which I could steal parts?

 

[N6BY]

I had an Amiko Mini HD SE with a similar problem - no output voltage, but it worked if power was applied to the other port of the C Band LNBF.

I remember tracing the voltage through the circuit and concluding that the problem was in the tuner chip, which was not available from Digi-key or Mouser. So I just discarded the receiver.

 

[cyberham]

That's disappointing. I hate to discard things that have minor problems. The microHD has the best tuning indicator I've seen for dish orientation. It has a 10-segment time-division display that helps you get the dish oriented dead centre on the signal.

 

[primestar31]

My problem symptom is simple. I have no LNB output voltage from this microHD. I have proved the receiver works fine if voltage is available to supply to the LNB. To do this test, I connected my Openbox S9 and used its loop through connector to connect the microHD. The microHD then works fine on the polarity selected by the S9.

My question: Does anybody know if there is an obvious voltage regulator chip in the microHD that could be changed to maybe fix this? There are no visually damaged components inside that are obvious such as blown electrolytic capacitors. But if I only needed to change something like a chip to fix then I would try. Even with surface mount chips which I wouldn't normally touch, I have nothing to lose as the receiver won't work as is. And, for nostalgia since it was my first good receiver, I'd like to get it working.

Does anybody have a schematic for this microHD? Or even an old discarded microHD not wanted from which I could steal parts?

Have you checked in the Settings menu, to make sure LNB voltage isn't turned OFF? If I remember right, there IS a setting to do that, to use it as a slave.

Titanium

 

[cyberham]

Yes, there is a setting for the LNB power. It's ON.

 

[cyberham]

Revisiting this issue just because I have time and I'm curious to see if I can fix this unit for no practical reason other than the technical challenge.

Asking again if anybody has the schematic diagram? There are few enough parts that maybe I can figure out which is a voltage regulator chip by comparing part numbers with sources on the Internet. Changing it would not be easy but what's to lose?