E3 error on display, compressor does not start or cycles off quickly, interior warms up

Warning: Work on compressor components only with the unit unplugged. Do not attempt to open the sealed refrigeration system.

• Access compressor compartment: Remove the rear lower service panel to expose the compressor and control box on the side of the compressor.
• Inspect start device: Remove the plastic cover on the compressor terminals. Check the CELLA compressor start relay/PTC and overload protector for signs of burning, cracking, or melting.
• Test continuity: With a multimeter, test the overload protector and PTC relay for continuity according to CELLA specifications. Replace the compressor start relay kit if readings are out of range.
• Check compressor windings: Measure resistance between the compressor terminals (C-R, C-S, R-S). Values should be finite and consistent with the nameplate. A short to ground or open winding indicates a failed compressor.
• Reassemble and test: Install new start components if needed, reattach the cover, restore power, and monitor operation. If E3 persists and the compressor hums then clicks off, the compressor may be mechanically locked and require professional replacement.