Patent ID: 8401407

Claim:
An image forming apparatus comprising: an attachment unit configured to receive at least one voltage; a holder configured to allow the attachment unit to be removably attached thereto, the attachment unit being replaceable with a test tool; a plurality of voltage generating circuits, each of the voltage generating circuits being configured to generate a predetermined voltage and to apply the predetermined voltage through a corresponding voltage line to the attachment unit attached to the holder; a controller for controlling operation of the plurality of voltage generating circuits, the controller being configured to control a first voltage generating circuit to generate a test voltage and apply the test voltage through a first voltage line, the test tool, and a second voltage line to a second voltage generating circuit in which a voltage generating operation is stopped, the first voltage generating circuit being one of the plurality of voltage generating circuits, the first voltage line corresponding to the first voltage generating circuit, the second voltage generating circuit being different from the first voltage generating circuit, and the second voltage line corresponding to the second voltage generating circuit; a current detecting section provided in at least one of the first and second voltage generating circuits, the current detecting section being configured to detect a current flowing through the attachment unit due to the applied predetermined voltage; and a deciding section configured to, upon the detection current corresponding to the applied test voltage and detected by the current detecting section as being equal to or greater than a first predetermined value, decide that the predetermined voltages are to be normally applied through the respective first and second voltage lines to the attachment unit.