Like a well performing vehicle, every now and then it’s good for your equipment to get a checkup to make sure that everything is running as it should be.
The procedures can vary for what is tested during a service, however the following is pretty standard for all:
Cleaning of all pots and switches with DeOxit Cleaner
Checking visually components, for both mechanical and electrical issues
Testing signal quality
Checking features are all working
Testing electrical parameters such as Bias, Supply voltages
Electrically testing components for wear and drifting of value