Nelson SmartZone EZ 8532 Shows "NO AC POWER": Transformer Replacement Guide

Fixing a Nelson SmartZone EZ Controller with No AC Power

The controller's LCD works but displays "NO AC POWER" and the sprinklers won't start. The user suspects the transformer and asks where to buy a replacement, noting the Nelson website no longer lists the SmartZone line and mentions "Signature" branding.

Diagnostic Steps

1. Verify 110 VAC at the transformer input.
2. If input voltage is present, measure transformer output: should be 20‑26 VAC.
3. Check the controller's backup battery—low battery can cause display issues.

Transformer Replacement

Almost any 24 VAC, ~0.5 A transformer will work if an exact Nelson part isn't available. Irrigation supply stores typically carry universal replacements. The "Signature" brand is the current Nelson product line.