NETGEAR Nighthawk RAX120 router restarts, freezes or overheats

The checks in more detail

If it shows an invalid value such as NaN, the sensor has failed, and the fan never speeds up when the router heats, so the router overheats and reboots. A router in that state needs a replacement under warranty, and the community says NETGEAR replaced such units. Owners who could not replace them at once added an external fan, a 140 mm one blowing across the top, which greatly reduced the reboots. Start with the basics that apply to every router. Take it out of the cabinet and into the open, with several centimetres around it and clear vents, since a closed cabinet traps heat. Power it off for sixty seconds and restart.

Use the original power adapter, since a lookalike gives unstable power. Plug it into the wall. Update the firmware, as NETGEAR has released versions that address stability, but read recent posts, since some releases caused trouble, and consider a rollback if the problem began after an update. Turn off features that raise the load, such as Armor, QoS and heavy logging, for a test. Check the log for the times of the reboots. Dust the vents with a dry brush. If the router is in a warm room, cool the room. If the temperature reading is valid and still high, the fan may be failing, which a repair or replacement can solve.

Check the warranty period. If the router reboots with a cool reading, good power and updated firmware, replace it. Back up your settings so that a replacement takes minutes. If you contact NETGEAR, give them the model, the serial number, the date of purchase and the reading from the thermal page, along with the dates of the reboots. A clear record that the sensor reads invalid gets the case moved to a replacement faster than a vague description. Keep the box and the receipt if you still have them, and save your configuration before the swap.