Ensure the firmware is for the 3840x2160 resolution. Flashing a 2K (1080p) file onto a 4K panel will cause a boot loop.
Once extracted, the file is usually named allupgrade_V960...bin . Do not rename it unless the specific instructions for your TV model say otherwise. The Update Process Turn off the TV and unplug it from the wall. Download CV960XH A50 3840x2160 Magic55 Update part20 rar
Hold down the on the TV cabinet (not the remote). Plug the power cord back in while holding the button. Ensure the firmware is for the 3840x2160 resolution
Many "Global Firmware" groups on Telegram host these multi-part files for Magic55 boards. Search for "CV960XH" in the global search bar. Download CV960XH A50 3840x2160 Magic55 Update part20 rar
The LVDS or V-by-One cable configuration must match, or you risk a "flipped" image or solarized colors.