Getting control board boot logs on Antminer
Board boot logs: when the web interface no longer answers
The ASIC does not come up, the web interface does not answer, the LEDs stay dark. In that situation the boot log is the only honest source of what is going on with the board.
The bench is the same one used for AML unlocking: the board, a 12 V power supply, a USB-UART adapter, PuTTY at 115200, GND to GND, RXD to LINUX_TX, TXD to LINUX_RX. The difference is that you leave the jumper alone. You just apply power and watch what the board says about itself at startup.
How to save the log to a file
Watching the terminal with your eyes is pointless: the lines scroll away in seconds. Set up logging before you apply power.
- In PuTTY open the Session section, then Logging.
- Pick the "All session output" mode.
- Set the file path, for example
C:\logs\board-01.txt. - Go back to Session, set the port and the speed to 115200, open the connection.
- Apply power to the board and wait until the stream of lines stops.
- Close the PuTTY window. The file is ready to send.
What to look for in the log
| What you see | What it means |
|---|---|
| The log stops at the first uboot lines | Trouble with board power or with the bootloader itself |
| The bootloader starts, the kernel does not come up | The NAND image is damaged, roll back from SD |
| The system boots but keeps rebooting in a loop | Usually a mismatch between the build and the board revision |
| Sensor read errors at the end of the log | Look at the hash board ribbon cables and the power |
| Nothing at all in the terminal | Wrong speed, RX and TX swapped, or the board has no power |
You do not have to read the whole log yourself. Capture it, attach it to your ticket, and the rest is support work. What else to attach is listed in the section on contacting support.