This refers to a specific software version or build (v558). Firmware updates for these boards are typically used to fix "hanging" logos, remote control issues, or to change the supported screen resolution.
These files are usually found on technician forums like Lab-One Forum or Dip Electronics Lab . Critical Handling Instructions
Using a "USB" firmware update is the easiest way to repair a TV that won't boot without needing a hardware programmer. Download RD8501 558 All Resolution USB part02 rar
Turn off the TV, plug in the USB, and then turn on the TV. If the board supports auto-update, the standby light should start blinking rapidly. Do not turn off the power during this process.
Because these boards are generic, installing the wrong version for your specific panel can result in a "mirror image," upside-down display, or a completely black screen (bricking the device). This refers to a specific software version or build (v558)
T-RD8501-03 USB Firmware Software Bios Bin - Lab-One Forum
Format your USB drive to FAT32 . A drive larger than 32GB or formatted to NTFS will often not be recognized by the TV's bootloader. Critical Handling Instructions Using a "USB" firmware update
is a common universal TV motherboard used in various budget LED and LCD TVs.