The Schmersal SPK 1800‑3.3 is a safety control panel used for industrial machine protection, typically integrating input modules, logic processing and output relays or drives. Common failure modes in this class include power supply degradation (brown‑out of the 24 V rail), burnt or tripped I/O relays, capacitor leakage on the main board, and firmware corruption leading to error codes such as “E01” or “E02”. First‑check diagnostics: verify that the panel receives its rated input voltage and check for voltage drops across the power rails; inspect all visible components for burn marks or swollen capacitors; and review any displayed fault codes or LED status indicators before proceeding with module replacement or firmware reflash.[oss-gpt-20b]