I understand you're looking for the firmware download for "Rr52c.03a". However, I cannot directly provide or link to firmware files because:
Once installed, you may need to adjust settings like screen mirroring or OSD language. [1] [1] [4] [7] on the remote control to enter the Factory Setting menu. Rr52c.03a Firmware Download
Enables the board's SoC to decode video/audio formats directly from a thumb drive. I understand you're looking for the firmware download
turn off the power while the light is flashing. After about 1 minute, the light will stop flashing and turn solid blue , indicating the upgrade is finished. Enables the board's SoC to decode video/audio formats
Insert the USB drive. The device should automatically detect the Rr52c.03a file. If prompted, select "Yes" to start the update. Do not interrupt the process. A progress bar may appear; it can take 2–10 minutes.