Diagnosis
A weak or intermittent spark is usually due to a corroded or misaligned electrode tip, or a nearly depleted battery in the piezo igniter module.
How to Fix It
Locate the ignition electrode for the problematic burner. It is a small ceramic and metal rod near the burner port. Ensure the electrode tip is clean and not coated in carbon. Gently clean it with a fine emery cloth. Check the gap between the electrode tip and the burner. The gap should be 1/8 inch. Adjust the electrode bracket to achieve this gap. Test the igniter.
If That Didn't Work
The piezo igniter module is located behind the control panel. The CGG-7400 uses a single module with a battery. Access the module (may require removing the panel) and replace the AA battery. Re-test.
Heads Up
When adjusting the electrode gap, ensure the electrode is not touching the burner. A grounded electrode will not spark. Also, moisture under the control panel can drain the battery and corrode connections.