The + button or – button does not work during certain jobs.
The appliance will fail to respond to the + button when the motor has already reached its maximum load, e.g. because you are processing large quantities of dough. This is normal and does not mean that the appliance is defective. Check the quantities mentioned in the tables in the instructions for use to prevent overloading the appliances. The appliance will not respond to the – button when the motor is already running at the lowest speed.