The SX-S Sonosax has two fuses: one for the external power inside the mixer, the other for batteries supply, inside the compartment itself.
To change the main power fuse, first remove the batteries compartment out of its place and unplug any external power supply.
Flip the mixer and lay it down on its top, unscrew the 6 bottom screws with the Allen key (1,5 mm) that could be found on the left panel of the batteries compartment and remove the cap.
The main fuse is located under the corner of the power ribbon cable, not far from its crossing with the main tranversal modulation wider cable, juste under the main faders.
Just lift up this narrower ribbon cable corner and remove the defective fuse.
Replace the defective fuse with a new identical one: 3.15 A T.
When screwing back the bottom panel, take care to correctly place the dedicated holes for the 12V mike power switches.