Freezer is making a loud buzzing or humming noise from the compressor area.

Safety first: Unplug the freezer before touching the compressor or tubing; components may be hot.

• Inspect mounting: Remove the rear lower panel. Check that the compressor mounting bolts and rubber grommets are intact and tight. Tighten loose bolts gently; do not overtighten.
• Check tubing contact: Look for copper refrigerant lines touching the cabinet or each other. Gently bend them away slightly and insert foam or rubber spacers to prevent vibration noise.
• Listen to start relay: If the buzzing occurs only at startup and the compressor fails to start, the start relay/PTC may be chattering. Replace it with a Hisense-compatible part.
• Monitor operation: After adjustments, restore power and listen. A steady low hum is normal; loud metallic or grinding noises from the compressor indicate internal failure.

If the compressor is excessively noisy or overheating, have a refrigeration technician evaluate it; compressor replacement requires specialized tools.