Support update:
Duet3D and Filastruder have excellent customer support.
I received my replacement board quickly and my printer is running again.
Filastruder packed the replacement board in with a new order and I added the Tool Distribution board for extra protection.
Thank you all.

Support update:
Duet3D and Filastruder have excellent customer support.
I received my replacement board quickly and my printer is running again.
Filastruder packed the replacement board in with a new order and I added the Tool Distribution board for extra protection.
Thank you all.

@Phaedrux
The 1LC board is flashing the red LED at about 2 flashes per second. The Duet 3 mini 5+ has a blinking red LED at around 1 per second, much slower. The PanelDue is showing 'response timeout: CAN' errors.
The 1LC also has red and blue LEDs on solid to the right of the blinking red LED. Unplugging the CAN connector on the 1LC has no effect.
The 1LC flashing red LED starts flashing the moment it gets power. No change in pattern.

I have successfully been using a Duet 3 mini with a 1LC V1.3 board attached to a Hemera XS for about 4 months. Today I heard a pop during printing and now the red LED on the 1LC is blinking and the Duet 3 cannot communicate with it over CAN. The 1LC looks OK, no obvious signs of damage. Holding both buttons for reset did nothing. Is there a simple fuse I can check, or is this tool board dead?

Purchased the 1LC V1.3 from Filastruder in July 2023.
E3D Hemera XS extruder, Revo heater and nozzle
Homemade Precision Piezo Orion carriage for nozzle Z sensing
Duet 3 mini 5+ wifi v1.02
Duet 3 Expansion Mini 2+