Hi all, new to this forum an electronic device repair. I have been given
a few items that are faulty to learn repair on and I currently am
working on a set top box the picture comes up fine but when I go to scan
the channels the signal strength is exactly 0 nothing at all, I have
tested various points on the board for voltage with a fluke and it all
checks out, the cables are fine. And im assuming the rf modulator box is
as well because im getting the display on screen when I plug the RF
cable in from the wall. Just no signal strength. I at a bit of a loss as
to where to start looking and cant find a service manual online to give
me any clues. the board is marked as DVB-TH MB04 rev 1.2. Some jaycar
product bought a few years ago. If someone could please point me in the
right direction it would be very much appreciated.

Thanks for your time.