The Raypak 601586 is a control board used in industrial heating and pool‑spa systems, typically handling power regulation, temperature sensing, and motor drive functions. Common failure modes for this class of boards include burned or cracked capacitors on the power input stage, damaged MOSFETs or IGBT modules controlling the heating element, and shorted or open traces around the temperature sensor interface; a secondary issue is often a failed optocoupler that isolates the control logic from high‑voltage sections. First‑check diagnostics should verify the 24 V DC supply to the board, inspect for visual signs of component damage (burn marks, bulging caps), and test continuity on the MOSFET gate drivers; if those pass, review any diagnostic fault codes logged by the associated PLC or display panel.[oss-gpt-20b]