Tegra k1 board is not booting.

Is this from serial console? What occurs right after this is HDMI port probing and HDMI setup for setting up console login ability. You might want to try boot with and without the HDMI monitor. In the case of “with” you might try unplug and re-plug of HDMI, or leaving HDMI completely unconnected up till this point and only then plugging in the HDMI.