Troubleshooting

Troubleshooting Guide

This guide covers the most common setup and configuration problems. Most issues are caused by USB cables, serial port selection, screen driver selection, unsaved settings, or incorrect input configuration.

Table Of Contents

Before You Begin

  • Use a data-capable USB cable. Some micro USB cables are charge-only.
  • Make sure no other program is using the serial port.
  • Press Enter a few times after connecting.
  • If you changed settings, enter save before disconnecting power.
  • If you changed map, airport, runway, or waypoint data, enter map save, then reboot to load the new map data.

Controller And USB Problems

Controller Is Not Detected

If the computer does not show a new serial port:

  • Try a different USB cable.
  • Try a different USB port.
  • Close any other terminal or configurator that may already be connected.
  • Reconnect the controller and check Device Manager or your system’s serial port list again.
  • If the controller recently had a failed firmware update, try loading the firmware again with Teensy Loader.

Terminal Opens But Nothing Happens

If the terminal connects but the controller does not respond:

  • Confirm that you selected the correct COM port or serial device.
  • Disconnect and reconnect the controller, then open the terminal again.
  • Press Enter several times.
  • Use 115200 baud, 8 data bits, no parity, 1 stop bit, and no flow control if your terminal requires serial settings.
  • Make sure another program, such as a configurator or another terminal window, is not already using the port.

Characters Look Wrong Or Unreadable

If you see random symbols or broken text:

  • Check the serial settings.
  • Use 115200 baud, 8 data bits, no parity, 1 stop bit, and no flow control.
  • Close and reopen the terminal after changing settings.

Controller Is Unresponsive

If the controller is completely unresponsive, it may be in recovery mode, have corrupted firmware, or have hardware damage from reversed power or 5 volts applied to a UART pin.

Use these checks before assuming the controller is dead:

  1. Check the LED between screen port 1 and the LED port. On current firmware, it should flash when the controller powers on. This LED is blue on most boards, but red on a few.
  2. If the board LED flashes several times, the board is likely working. If it comes on solid, the controller may be damaged.
  3. Check the LED next to the white button on the Teensy board. It is orange and should flash very fast. It may look like it is solid on. If it is on, the board should be working. If it is off, continue to the next test.
  4. Press the white button. A small red LED next to the USB connector should come on. If it turns red, try reprogramming the firmware.
  5. If that does not work, try Full Erase And Restore.

Full erase restores the controller back to a basic flashing LED program. The controller can then be flashed with new firmware.

If none of these tests pass, the controller may need repair or replacement. See the Warranty page.

Display Problems

Screen Is Blank, White, Shifted, Or Upside Down

If a display does not look right:

  • Select the correct screen.
  • Choose the correct driver for the display resolution and LCD controller type.
  • Use invert, flip, rotate, or mirror if needed.
  • Try a different driver if the screen is blank, white, shifted, mirrored, or only partially drawn.
  • After changing display settings, enter save and reboot the controller.

For display driver information, see Display Info and CLI Commands.

Wrong Colors On A Screen

Some screens, especially small round displays, may show inverted colors by default.

  • Use the invert command.
  • If the image is still wrong, verify that the driver matches the display.
  • After changing the setting, enter save and reboot the controller.

Parts Of One Screen Appear On Another Screen

If you see screen data bleeding into the next display, the next screen may be starting before the previous display has fully released.

  • Use drawdelay 3.
  • If needed, increase to drawdelay 5.
  • After changing the setting, enter save and reboot the controller.
drawdelay 3
save

Settings And Map Problems

Settings Disappear After Power Is Removed

If changes do not stay after reboot:

  • Make sure you entered save after changing settings.
  • Reboot the controller after saving.
  • If the setting still does not save, try settings reset, then configure and save again.
save

Map Changes Do Not Load

If new airports, runways, or waypoints are not showing:

  • Enter map save.
  • Reboot the controller.
  • Confirm the map data was entered correctly.
  • For firmware 1.12 and newer, use the updated runway format.
map save
reboot

Map setup tools are available here:

Input And Telemetry Problems

GPS Or Telemetry Data Is Missing

If the system is not showing expected flight data:

  • Confirm the input source is correct.
  • Check the flight controller connection.
  • Make sure the correct UART speed is selected if using MSP or MavLink.
  • Verify that the selected input type matches your setup.
  • Confirm the flight controller is actually sending the expected data.

For input setup information, see Input Sources.

Reset Settings

If the controller is not working correctly, or if settings become corrupted, start with settings reset. This reloads default controller settings while keeping the current display setup.

After resetting settings, enter save before disconnecting power.

settings reset
save

Use settings default only when you want a full factory settings reset. It resets display drivers and screen setup too, so you may need to select screen drivers, orientation, display modes, and layouts again.

settings default
save

After resetting settings, reenter any custom setup values needed for your input source, map data, runway data, or radio channels. If you used settings default, also reconfigure your screens.

Full Erase And Restore

If the controller is stuck in a bad state, you can try a full erase of firmware and settings.

Use this only if normal troubleshooting, settings reset, and settings default do not fix the problem. A full erase removes the firmware and settings, then restores the controller to its original Teensy state.

  1. With the controller powered off, hold down the white button.
  2. Power on the controller while continuing to hold the button.
  3. Keep holding the button until the small red LED near the USB connector turns on and starts blinking. This may take 20 to 30 seconds.
  4. Release the button and wait while the controller erases the flash and restores the default blinking LED program.
  5. When the orange LED next to the button starts flashing, the controller is back to its initial state and is ready to be programmed.

After the erase is complete, use Teensy Loader to load the latest FPVToys firmware.

Firmware update instructions are available here: Update Firmware

Still Having Trouble?

Use the following pages for setup help:

If the issue continues, use the Contact page and include:

  • Your flight controller type
  • Your input source
  • Your screen type and driver setting
  • The exact problem
  • A photo of the screen or wiring if possible

Contact FPVToys

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