The fuse used depends on the year of manufacture and serial number of the device: fine fuse 5x20 mm, 16A, fast-acting (up to serial number 2051XXXXXX) and fine fuse 5x20 mm, 16A, ultra-fast (from serial number 2115XXXXXX)
Each channel is fused individually on the channel board. The fuse is located in a fuse holder directly below the connectors for the triac and the phase lines of the channel.
Carefully lever the defective fuse sideways out of the fuse holder using a flat screwdriver.