Error Code The appliance does not come on; The main switch (A8) is not turned on.

Power supply issue traced to faulty activation of primary control mechanism.

? What Causes This

Failure or improper setting in master power toggle located at back affects overall operational readiness.

✓ How to Fix It

Position main switch appropriately as per schematic diagrams and proceed sequentially with other checks detailed under maintenance instructions (fig.3, page 9-10 setup guidelines). Refer to troubleshooting tips outlined on pages describing these setups for precision.

Source: page 18 of the official manual

From the manual

Manual page 18 — De'Longhi error The appliance does not come on; The main switch (A8) is not turned on.

This error code appears in:

De'Longhi Magnifica XS Ecam22110b