Hello JohnnyMarh,
Let's start off by checking the helpful steps in this article which can help with this issue: Connect iPhone to a display with a cable - Apple Support. Follow these simple steps:
- "Plug a Lightning Digital AV Adapter or Lightning to VGA Adapter into the charging port on the bottom of iPhone.
- Connect an HDMI or VGA cable to the adapter.
- Connect the other end of the HDMI or VGA cable to the monitor, TV, or projector.
- If necessary, switch to the correct video source on the monitor, TV, or projector. If you need help, use the display’s manual."
If those are the steps you are taking, and you've ruled out the cables and TV being a source of the issue (by testing with your iPads and other adapters/cables), then further assistance may be needed. We want to make sure you reach the right team for help with your device, so we recommend that you contact Apple Support directly. Depending on your region, you may be able to reach them here: Get Support.
Thank you for participating in the Apple Support Communities and have a wonderful day.