The Sx-70 camera is an electronically controlled device, the electronics being in the integrated circuits (IC) mounted in the Electronic Control Modul (ECM) and Flash Fire Assembly (FFA) in the shutter housing and in the Motor Control Circuit (MCC) in the camera back. Because the IC’s are non-reparaible items, there is no requirement to trace faults whithin the integrated circuits. It is mandatory, however, to be able to identify the command inputs (switches open or closed, etc.) and the resulting output signals. The SX-70comprehensive Tester provides the readouts necessary to confirm an exposure malfunction; but thorough understanding of the theory of operation is required if meaningful use of the tester is expected. If a particular camera function fails, it is necessary to recognize how the failure is related to the operating sequence of events and thus reduce testing procedures to those related to the aera malfunction.
Because of the camera’s total automation, it is unlikely that much useful guidance can be obtained from customer complaints except in cases of visible mechanical damage. For this reason, a well defined series of checks, observations, and tests must be followed. This section of the manual defines these procedures.
The primary purpose of any fault analysis program is to reduce the investigation time to a minimum. Thus, it is not only important to establish a fixed routine, but it is mandatory to acquire the maximum amount of information from each step of the checkout procedure. Use the charts at the end of this section to guide through each step of inspection, dynamic testing and post-repairs tests.
Analysis of the SX-70 camera is a key part of the complete repair task. If the analysis is done correctly, it will eliminate excessive repair time and high parts replacement cost. For instance, initial evaluation may show the entire shutter to be at fault; however, continuing analysis determines that the problem is in solenoid #2, which, when replaced reduces the materiel cost considerably (from over 20 $ to under 2 $). The repair person must always consider the labor vs. material trade-off when making a repair.