Spellman 7681 (X2890) is a high‑voltage power supply used in GE Lunar Prodigy/DPX bone densitometry and radiology systems, typically delivering up to 40 kV for X‑ray generation. Common failure modes include degraded output regulation due to aging MOSFETs or rectifier diodes, overheating of the internal transformer windings, and loss of safety interlocks caused by failed opto‑couplers or latch‑up protection circuits. First‑check diagnostics should verify that the unit receives proper input voltage and current from the mains supply, inspect for visible signs of burn or corrosion on the PCB and component leads, and confirm that all output fuses and protection relays are intact before proceeding to a detailed test of the high‑voltage output with an isolation meter.[oss-gpt-20b]