Sharp NC-II core Assembly for television, some brands of OPC, commonly known as the cat's eye. When the user presses the OPC button, can automatically track the external lighting conditions and automatically adjust the brightness, contrast and color saturation of the TV, when OPC gets out of control, push button is invalid. When the photosensor CDS1001


Or control transistor Q1001 failures will enable the OPC is out of control.
Switch off the machine, use a multimeter measured photosensor Rx1k ω CDS1001 resistance, OPC box cover Panel with hand, resistance value changes, normal resistance on her big, but small. This example to work.
In road measurement Q1001 collector and emitter junction of forward and reverse resistance and found it both forward and backward and remove the measure be open. Replacing a 2SA1015. OPC is normal. In the absence of this tube, high beta category 3CG can be used instead.