Community-driven platforms such as Kazmi Elecom or Softwarezone.ga are common sources for split RAR files like the "part01" you mentioned.
If you manage to download the firmware (usually in .bin or .img format after extracting the RAR), the general installation steps are: Download ONIDA LEO43FIAB2 Software part01 rar
Press and hold the on the TV panel (not the remote) and plug the TV back in. Keep holding until the "Software Updating" screen appears. Online System Update Download ONIDA LEO43FIAB2 Software part01 rar
Do you have the from inside the TV to ensure you get the exact matching file? Softwarezone.ga Download ONIDA LEO43FIAB2 Software part01 rar
Place the firmware file (often named allupgrade_...pkg or MstarUpgrade.bin ) into the root directory (not inside a folder). Flash Firmware: Power off the TV and unplug it. Insert the USB drive.