Topward 3603D is a single‑channel DC power supply rated at 60 V/3 A (180 W) with built‑in constant‑voltage and constant‑current output, short‑circuit protection, and optional serial or parallel connection to other units. Common failure modes include tripped over‑current relays, degraded internal capacitors causing ripple or voltage drift, and burnt fuse contacts in the power input section. First‑check diagnostics: verify input mains voltage and polarity on the supply’s AC inlet; confirm output voltage with a calibrated multimeter while monitoring for sudden drops or oscillation; inspect the main power transformer and rectifier diodes for signs of overheating or cracking.[oss-gpt-20b]