Unmatched boot issues

Hi all, I was using my unmatched for a while just using Ubuntu. Then one day I couldn’t boot it any more. I have tried debugging:

I get no output from any serial device and all I get on the board is the fan spinning and D2 LED is always red (I think it’s uninitialized so could be anything), other two D9/D20 are always green.

Is there anything else I can do or am I out of luck?

Thanks for any help!

Well, looks like it’s dead then. Anyone want parts? I’ll leave it a few days then throw it away

e…Is it free?

Hi Yuumei,

  1. Confirm the power supply: Ensure that the board is receiving stable power with the correct voltage and current capacity. A fluctuating or insufficient power supply might cause booting issues.
  2. Verify UART connections: Double-check the connections for UART (Universal Asynchronous Receiver-Transmitter) via GPIO on UART0 or UART1. Ensure that the connections are correct, and there are no loose wires.
  3. Check UART settings: Make sure that the UART settings such as baud rate (115200), data bits, stop bits, and parity are set correctly to match the configuration of your board.
  4. Verify the MSEL positions: Confirm that the MSEL (mode select) pins on your board are set to the correct configuration for booting from the desired source (e.g., SD card, JTAG, etc.). You will need to modify MSEL to allow using U-Boot SPL, OpenSBI, U-Boot proper bootloaders from uSD card instead of SPI-NOR Flash chip.
  5. Test with different SD cards: Try using different SD cards with the “standard” GPT partition layout, and verify that they are properly formatted and contain the required boot files.


Hi Shree,
Thank-you for the response. If you read my message you will see I have done every step you have described already, apart from checking the voltage levels.I have verified 3.3, 2.5 and 1.05V rails are working as expected

Could you explain what the various states of the boot LEDs mean?

There are two user programmable LEDs present on the board, which provide bootflow and status information by signaling the boot stage with a Red-Green-Blue (RGB) LED and by blinking a
green heartbeat function LED.

Table: Board D2 reference designator RGB LED function

  1. Undetermined: Default state
  2. Yellow: U-Boot SPL (very short run time).
  3. Purple: U-Boot proper was entered.
  4. Blue: extlinux is about to start sysboot.
  5. White: systemd-udevd will set it during kernel boot (past init process start).
  6. Green: Will be set 3 minutes after system is booted into basic.target and console is available.

Table: Board D12 reference designator Green LED function

  1. Blinking: The kernel booted and running. This is driven by the Linux kernel’s “heartbeat” function, and only starts blinking after the kernel starts
  2. NotBlinking: The kernel is hanged/crashed.
  3. Blinking fast: The workload on the system is very high.

Since the dual-color LED on your board shows red it probably means that it is not initialized.
Red is not one of the documented states in SW reference manual’s table-2. Sometimes I have seen the LED turn RED or not even turn ON when SD-Card is not inserted.

Here are some HW debug options:

  1. If you have a JTAG dongle then it can be checked whether it is possible to connect to the SOC and check its program counter.
  2. If you have access to an oscilloscope you can check the SD-Card’s CS0 signal on R21’s pin 4 whether it asserts when the board comes out of RESET. If it does not then the SOC might be toast but if it does then it would be worthwhile checking if the SOC tries to upload the code.
  3. If you have a SPI decoder then it can be attached to R172/R182/R34/R210 but that would require soldering and might not be a feasible option.