Convertec S1K8001999 is a compact industrial AC‑to‑DC printer power supply that delivers regulated DC output from 90–135 VAC input. Common failure modes for this model include degraded electrolytic capacitors on the rectifier bridge, failed silicon diodes or MOSFETs in the switching stage, and overheating of the internal transformer due to prolonged high ambient temperatures. First‑check diagnostics: verify incoming AC voltage and polarity; measure output DC rails with a multimeter while the unit is powered on; inspect for bulging or leaking capacitors, burn marks, and ensure all fuses and protection relays are intact. If outputs are out of spec, proceed to component replacement or rebuild the rectifier bridge.[oss-gpt-20b]