11 Maintenance, servicing, removal, error messages11.1 CleanBefore cleaning, disconnect the appliance from the operating voltage.Please do not use aggressive cleaning agents (solvents or similar agents), but acloth dampened with mild soap suds. Take care that the device is not penetrated byfluids and polish it with a dry soft cloth.Loose residue sample/powder can be removed carefully with a brush or manualvacuum cleaner.Spilled weighing goods must be removed immediately.11.2 Servicing, maintenanceThe appliance may only be opened by trained service technicians who areauthorized by KERN.Before opening, disconnect from power supply.11.3 DisposalDisposal of packaging and appliance must be carried out by operator according tovalid national or regional law of the location where the appliance is used.11.4 Error messagesERR 4 Zero range exceededERR 5 Invalid entryERR 6 Damaged electronicsERR 8 Adjustment error: wrong adjustment weightERR 9 Instability when the balance is switched on38 GAB-P-BA-e-1411