Servicing the Sharp DA100 (50Hz) and DA50W chassis

摘要

As with all recent Sharp TV chassis, the main microcontroller chip (CPU) IC 1001 is responsible for control of the set. It communicates with other areas of the chassis via various data buses but, as with similar chassis, it doesn't operate during standby. There is therefore a need for some form of control on the primary side of the power supply. A slave processor (IC702), which is connected to the main microcontroller chip via two optocouplers (in/out), is used for this purpose. The slave processor has a volatile memory, thus each time power is applied to a set the chopper circuit has to start up so that the slave processor's program can be downloaded from the EPROM/OTP/MTP (depending on model) chip IC 1002 via IC 1001. The set can then switch to standby. The remote-control receiver is connected to the slave processor chip. Fig. 44 shows the control system in block diagram form.