The Staefa 091‑60200‑82 is a control board used in industrial PLC and HVAC control systems, typically mounted as an add‑on module on Siemens or Staefa Smart II chassis. Common failure points for this class of boards include burnt or cracked surface‑mount components (especially power MOSFETs and voltage regulators), degraded solder joints at the I/O connectors, and failure of the integrated microcontroller due to over‑voltage or thermal cycling. Initial diagnostics should verify that the board receives its rated input voltage and current, inspect for visible damage or overheating on key ICs and power components, and check all I/O pins for proper signal integrity and continuity before proceeding with a full functional test.[oss-gpt-20b]