Biesse NC400 is a CNC numeric control unit used in wood‑working centers, featuring a color touch screen, keypad, and IP54-rated enclosure. Common failure modes for this model include power supply board faults (brownouts or tripped fuses), display panel glitches, and communication errors with the machine’s drive electronics; overheating of the main PCB can also trigger intermittent resets. First‑check diagnostics: verify 24 V DC input voltage and confirm all connectors are seated; inspect the power supply board for burnt components or swollen capacitors; review any error codes displayed on the screen or logged in the controller’s diagnostic menu, then test I/O signals to the drives with a multimeter or oscilloscope.[oss-gpt-20b]