Pressing the MENU button on the remote brings up the main interface. Here is what the standard tabs usually look like:
On page 42, buried in a footnote about SCART adapters, is a cryptic line: “For advanced users: long press ‘INFO’ while booting to enter diagnostic mode.” No explanation of what that mode does. The manual just leaves you there, alone with your curiosity and a blinking red LED. That’s either a bug or a gateway to heaven. I still haven’t tried it. humax hv100-03 manual
Since you are searching for the manual, you likely need help with physical installation. Follow this sequence. Pressing the MENU button on the remote brings