A:Answer Hello there, Chris. Thank you for reaching out. We understand you're having trouble using an HDMI 2.1 to Thunderbolt 4 adapter with your LG OLED48B4PUA TV and would like to know if the HDMI inputs have different capabilities.
This model features four HDMI inputs, all of which support 4K at 120Hz, Variable Refresh Rate (VRR), Auto Low Latency Mode (ALLM), and HDMI 2.1 features like eARC. However, not all HDMI ports support the full range of features at all times. Specifically, HDMI 3 is the one with eARC support, but all four HDMI ports are capable of high refresh rates, VRR, and 4K resolution.
Regarding your HDMI 2.1 to Thunderbolt 4 adapter, there could be compatibility issues between the adapter and the TV, as Thunderbolt 4 typically requires specific support from both the laptop and the display device. To ensure compatibility, it’s important to confirm that your laptop’s Thunderbolt port supports video output through HDMI 2.1 and that the adapter is designed to handle the bandwidth and resolution needed for 4K output.
We recommend trying another HDMI cable or direct HDMI connection to rule out adapter compatibility issues. Additionally, ensure that your laptop's settings are configured to output video to the HDMI port.
https://www.lg.com/us/tvs/lg-oled48b4pua-oled-4k-tv#pdp_specs
If the issue persists, please send us a private message on Social Media @LGUSSupport, and our team will be happy to assist you further.
—Renzo
