Sudance Spa 850LCD Power Supply board/Relay Board Repair Service

Professional diagnostic and board-level repair service for this Sudance Spa 850LCD Power Supply board/Relay Board.

The Sundance 850LCD power‑supply/relay board is a controller module used on 1‑ and 2‑pump hot‑tub systems from the late 1990s through current models (e.g., PWA‑850, NT variants). Common failure modes include burned‑out MOSFETs or driver ICs due to overheating, capacitor degradation in the power section, and firmware corruption on the EPROM. Typical symptoms are loss of pump operation, erratic relay cycling, or a “power supply fault” message on the LCD. First‑check diagnostics: verify 120 VAC input voltage and correct polarity; inspect the board for visible burn marks or swollen electrolytics; test the relay contacts for continuity and check the MOSFET gate voltages with an oscilloscope to confirm proper drive signals. Post Comment

Need your Sudance Spa 850LCD Power Supply board/Relay Board repaired?

Ship your unit to our North Carolina repair shop for component-level diagnostics and a repair estimate. We service industrial control electronics and power systems nationwide.

• ⚙️ Board-level diagnostics – Troubleshooting beyond simple module replacement
• 🔁 Clear approval process – No repair begins without your approval
• 🧰 Expert Technicians – Decades of board-level experience
• ✅ 1-Year Warranty – Included with completed repairs

Start a Repair Request   Call 1-336-969-0110

Nationwide service • Industrial-grade testing • 1-year warranty on completed repairs

Owner-Operated • Practical Pricing • 1-Year Warranty • Nationwide Service

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