Panasonic TC-26LX20 Technical Manual

Also see for Combo TC-22LR30: Operating instructions Service manual

Panasonic TC-26LX20 Technical Manual Manual pdf 12 page image

System Control BlockThe control signals responsible for the overall operation and control of both units areshown in this diagram along with their designated termination points. Main Power switch signal is derived from the power on switch, which is located onthe K board. The Main Micro (TV Microcontroller), located on the DG board, seesthis as a “key scan” input signal and issues a TV ON and AC_On to the controlcircuitry within the Primary and secondary power supply. DVD Power switch signal is derived from the DVD operation switch, located on theDVD OP board. This signal is responsible for initiating the power on sequence forthe DVD operation. The Main Micro sees this as a “key scan” input signal. Panel ON signal appears on pin 28 of the DG board connector DG2. This isequivalent to an on/off switch for the LCD Panel. Backlight ON /OFF (B/L On/Off) signal provides the enable for the DC to ACbacklight inverter power supply which is incorporated within the LCD Panel. OSD Timing Compensator synchronizes the OSD with the incoming video. System ShutdownThe Main Micro on the DG board is responsible for monitoring the various shutdownconditions. The Main Micro monitors the SOS and main voltage (Zero X Detect)detection signals via the DG2 connector. LED Functionso The Time Warp Led indicates that the DVD is recording at twice the normalrecord mode (operator’s choice)o The SD LED indicates that the SD card is being accessed either for a read ora write operationo The DVD LED indicates that the DVD unit is being accessed either for a reador a write operation TV Data In/Out are DVD control lines used for playback and record. DVD Play switches the audio monitor output from all audio inputs to the DVDOutput. Wake Up provides Serial data communication between the DVD Micro and MainMicro. Fan Control is accomplished through the use of a fan control circuit located on theDVD main circuit board. A PWM output signal from sub processor IC 7501 controlsthe speed of the fan, based on the internal ambient temperature of the unit7