If you have completed the software adjustments and the signal remains unstable, the issue lies within the TV's physical port sensitivity. You can circumvent this using external hardware tools: Use a Powered HDMI Splitter
Arthur hooked up his signal generator to test the RF input. He dialed in a test pattern. The TV520 R1 locked onto the signal instantly. The geometry was perfect. The corners of the image didn't sag; the lines were razor-straight. It was engineering from an era when things were built to outlast the people who bought them. philips tv520 r1
The “R1” in the name often refers to the and remote control model. Firmware updates are available via USB from Philips support site when released, but no automatic updates for SAPHI apps typically. If you have completed the software adjustments and
⚠️ Note – this model does support Android TV or Google Cast (Chromecast). No official HDR support. The TV520 R1 locked onto the signal instantly