In the troubleshooting of camera. In addition to the power supply circuit. Failure of the control system of automatic aperture is rare. The machine troubleshooting of aperture control system flow chart as shown. Below is the common fault of maintenance method. tHHservice manual download site
 tHHservice manual download site
(1) when shooting in the viewfinder image, but replay show normal image. tHHservice manual download site
 tHHservice manual download site
Such failures are within the lens aperture ring cannot be opened. For diagnosis can be unloaded machine cover, in current instantaneous observation aperture ring can be action, if not, explain the aperture ring cannot be opened. Cause of aperture ring can't open has the following several ways: aperture ring on a chip with too much dust; The aperture ring got stuck sand; The aperture ring piece of serious deformation; Work is not normal aperture automatic control circuit. If the aperture ring on a chip with dust or sand stuck. Use brush to remove; If the aperture ring serious deformation, only the switch to a new aperture components: if the aperture work abnormal automatic control circuit, lead to aperture can't open, is the key check the light meter aperture. tHHservice manual download site
 tHHservice manual download site
 tHHservice manual download site
Adjust potentiometer VR701, aperture motor drive pipe Q701, aperture and 5 v power supply circuit. tHHservice manual download site
 tHHservice manual download site
(2) in the environment brightness is dark, the image of the normal, and in the environmental brightness is higher, the image of the white. tHHservice manual download site
 tHHservice manual download site
This situation shows the aperture opening range is larger, always cause CCD receives the image brightness is strong, should focus on check: whether the aperture ring plate is stuck; Whether VR701 damaged; Whether IC704 damage or performance becomes poor. If the measured voltage can vary with environmental brightness IC704 6 foot, but 7 feet voltage does not change, then IC704 has been damaged. Check if the above circuits and components are normal, check respectively R736, R725, Q701 and related components.tHHservice manual download site