E5 error on display, compressor may not start or may run only briefly before stopping.

Safety first: Unplug the freezer. Work near the compressor only when power is disconnected. Refrigerant system must not be opened by unqualified persons.

Steps:

• Access compressor compartment: Remove the rear lower service panel to expose the compressor and electrical box.
• Inspect wiring: Check that all wires to the compressor, start relay/PTC, and overload protector are firmly connected and not burnt.
• Check start relay/PTC: Remove the relay/PTC from the compressor terminals. Shake it gently; if it rattles excessively or shows signs of burning, it is likely faulty. Measure resistance according to the service manual; replace if out of spec.
• Test overload protector: With a multimeter, check continuity through the overload device. If open at room temperature, replace.
• Reassemble and test: Fit new Grundig-compatible start relay/PTC and overload protector, reconnect wiring, and power on. Listen for the compressor starting smoothly.
• Compressor condition: If E5 persists and the compressor hums then clicks off, the compressor itself may be seized or internally damaged. This requires a sealed-system repair by a certified refrigeration technician.