The Allen‑Bradley 8200 Resolver board (part 93808801) is the signal conditioning module that interfaces a Brown & Sharpe resolver with an Allen‑Bradley PLC or drive controller. Common failure modes include loss of resolution output, error code 4000 (resolver fault), and DVO (digital voltage out‑of‑range) indications; these are often caused by damaged input/output traces, failed op‑amps, or degraded power‑supply decoupling on the board. First‑check diagnostics: verify 24 V DC supply to the board and confirm proper grounding; inspect for visible burn marks or cracked solder joints on the resolver connector pins; review PLC error logs for 4000/8000 series codes and cross‑reference with the resolver status register. If faults persist, perform a continuity test across the resolver input traces and replace any op‑amps that show abnormal voltage levels.[oss-gpt-20b]