Display shows Power Error or flickers; unit resets unexpectedly

Safety first: Disconnect the unit from the mains before inspecting electrical components. Only perform electrical tests if you are comfortable and qualified.

Step-by-step checks:

• 1. Check outlet: Plug a lamp or tester into the same outlet to confirm stable power. Avoid switched outlets.
• 2. Inspect transformer: Verify that the Marlo transformer is securely plugged in and that the low-voltage plug is firmly connected to the control board.
• 3. Measure transformer output: With a multimeter set to AC, measure the secondary voltage. It should match the rating on the transformer label (commonly 24 VAC). Replace if significantly low or zero.
• 4. Inspect control board: Look for burnt spots or bulging components near the power input section.

When to replace parts: Replace the Marlo low-voltage transformer if output is incorrect. If a good transformer does not resolve the issue, replace the Marlo control board.