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.