Cause: Low battery voltage (<6V), EdgeTX software RTC data corruption, or SD card issues.

Solutions:

  1. Check Battery Voltage

    • Use a multimeter to ensure the battery pack voltage is above 6V.

    • Charge or replace the battery if below 6V.

  2. Reset the RTC by Removing the Button Battery

    • Power off and disconnect the main battery.

    • Remove the back cover, locate and remove the button battery from the motherboard.

    • Wait 1-2 minutes to drain residual power.

    • Reconnect the main battery (have not reinstalled the button battery yet).

    • Power on. If it works, please reinstall the button battery.

    • Note: This issue is fixed in EdgeTX v2.10.0+ (latest v2.10.5).

  3. Update Firmware Using EdgeTX Buddy

    • Download EdgeTX Buddy: buddy.edgetx.org.

    • Install STM32 driver: edgetx.org/faq.

    • Power off TX16S, remove the main and button batteries.

    • Connect TX16S to the computer via a top USB port (no batteries needed; USB powers the chip).

    • In EdgeTX Buddy, select "RadioMaster TX16S" and flash the latest firmware (v2.10.5).

    • Follow: edgetx.gitbook.io.

  4. Replace SD Card

    • If issue persists, replace SD card (format as FAT32).

    • Bad blocks on SD card may corrupt RTC Backup RAM, preventing boot.

Note: RTC data errors may occur from sudden shutdowns or SD card issues, causing boot failure even after firmware updates. Resetting RTC clears corrupted data.

Still Not Working?

  • Contact support at support@radiomasterrc.com with your order details (e.g., Order ID, Serial Number).

Last Updated: May 06, 2025