Patent ID: 8217974

Claim:
A method of refurbishing a customer replaceable unit for installation in a printing apparatus, the customer replaceable unit including a high voltage power supply unit configured to transform low voltage electric power into high voltage electric power for use by a component of the customer replaceable unit, the power supply unit including at least one of a transformer, a rectifier, a filter, and a regulator, and the method comprising: replacing or repairing the component and the at least one of the transformer, rectifier, filter, and regulator in the customer replaceable unit prior to installation of the customer replaceable unit in the printing apparatus, wherein the customer replaceable unit includes a low voltage signal input, and the high voltage power supply unit controls output of the high voltage electric power in response to signals received at the low voltage signal input, and said replacing or repairing of the component is performed without having to alter said signals, said signals comprising a set of interface commands independent of a type of the component and independent of a type of the high voltage power supply unit, said signals indicating a desired output of the high voltage power supply unit.