Documents and Downloads
Frequently Asked Questions (FAQ)
The K300 contains a microcontroller which among other things, controls the timings. You can read more on the controller here: https://support.onlogic.com/onlogic-systems/rugged/karbon-series/karbon-series-using-the-serial-interface
Check out our Update Guide here:
802.3at – up to 25.5 watts per port.
PD Voltage: 42.5 V – 57.0 V
Maximum Amperage: 600 mA
Repeatedly press Del to enter the BIOS and go to Chipset > Auto Power-On
The microcontroller and CAN ports are addressed via /dev/ttyACM0 and /dev/ttyACM1. The physical COM ports are /dev/ttyS0 and /dev/ttyS1.
Enabling Auto Power On
Press Del to enter the BIOS and go to Chipset > Auto Power-On
Opening the K300 will not void your warranty, but you must take adequate ESD precautions to avoid damage caused by static electricity. A grounding strap is recommended.
- Begin by removing the 4x Torx T10 screws from the case
- Slide and flip the bottom cover off as shown.
- Refer to the following motherboard schematic for component installation
- Apply thermal pads from the accessory kit to any hardware installed
- Hinge the bottom cover back on
- Reinstall the case screws
Resetting the microcontroller
The onboard microcontroller (MCU) can be reset to resolve some boot issues, and to restore the MCU.
- Unplug the K300 from DC power
- Using a paperclip or similar object, depress the small button inside the Settings hole
- Continue to hold the button down and plug in and power on the K300
- The Watchdog LED will flash rapidly. The MCU has now been reset.
- The watchdog LED will return to normal after the next reboot.
If the MCU reset does not restore the K300 to working order, the next step is to disassemble the unit and clear the CMOS. Instructions for doing so can be found in the next section.
Clear the CMOS
If the system fails to power on or otherwise function, clearing the CMOS may help restore it to a working state.
- Unplug the unit from power and follow the disassembly steps above
- Locate the clear button next to the battery and supercapacitor
- Depress the button with a flathead screwdriver, fingernail, or similar object for 30 seconds
- The CMOS is now clear. Power the unit back on. It may reboot multiple times before resuming normal operation.
- If you continue to see issues, contact technical support.
Issuing using the Microcontroller
If you’re seeing issues using the system’s microcontroller (MCU), make sure you’re running the latest firmware version. You can check your current version by opening a connection to the MCU and running the
If the MCU in inaccessible, or needs to be updated, you can update the MCU firmware by following our Update guide:
No audio in Linux workaround
As of this writing (4/14/2021), there is a known issue in Ubuntu 18.04 and 20.04 that causes DisplayPort audio not to work. As a workaround, one of the audio kernel modules needs to be blacklisted.
To do so, open a terminal and run the following commands:
echo "options snd-hda-intel dmic_detect=0" | sudo tee -a /etc/modprobe.d/alsa-base.conf
echo "blacklist snd_soc_skl" | sudo tee -a /etc/modprobe.d/blacklist.conf
Reboot the system, and DP audio should once again be functional.
Further details can be found on this page.