Display shows E4 and the coffee maker will not start a brew cycle, often accompanied by a beeping sound.

Safety first: Unplug the coffee maker before manipulating the lid or basket area to avoid accidental operation.

• Reseat the brew basket: Remove the filter basket, clean any coffee grounds from the rim and support rails, and reinstall it fully until it clicks or sits flush.
• Close the lid firmly: Press down on the lid until you hear or feel a click. Some Insignia models require the lid to be fully latched to close an internal safety switch.
• Inspect the lid tab: Look for a small plastic tab or protrusion on the lid or basket that presses the internal switch. If it is bent or broken, the switch will not engage. Minor warping can sometimes be corrected by gently reshaping the plastic when warm (use caution).
• Check for obstructions: Ensure no coffee scoop, filter edge, or foreign object is preventing the lid from closing completely.
• Switch test (advanced): With the unit unplugged and the top cover partially removed, locate the lid microswitch. Manually press the switch and check for a distinct click. A loose or non-clicking switch likely needs replacement.

If E4 persists after confirming proper closure, the lid switch or its wiring harness may need to be replaced.