...instrukcja serwisowa w pełni czytelna i kompletna. Dziękuję!
Tekstowy podgląd strony 8 (kliknij aby zobaczyć)
Switch-on sequence.
In 1. 2. 3. 4. 5. 6. 7. 8. 9. case of malfunction it is very important to know the switch-on procedure: The microprocessor starts working when the reset goes low. It reads from NVM the last ON/STAND-BY state. If state is ON, it continues the switch-on procedure. It waits for a falling edge in the 16/9&BSYNC line. The port B_HIGH is set to switch the power to SMPS_B_HIGH state. It waits for a rising edge in the 16/9&BSYNC line. It reads the CTL1 signal. If this signal doesn�t rise before 160mS the process is stopped indicating ERROR_4. It checks PD_FAIL and CTL2 lines. If any of them is high, the process is stopped indicating ERROR_7. The Video processor is started via I2C bus. If there isn�t any answer the process is stopped indicating ERROR_1. 10. There is a 1 second delay. 11. The deflection is started. If there are failures the process is stopped indicating ERROR_2 or ERROR_3. 12. It waits until the cathode heater is warm by inspection of the video processor register bit AKB. 13. Finally picture and sound are switched on.
Protect modes and failure indication
The microprocessor continuously checks the different parts of the circuit and if it detects any fault in a safety defined part then it puts the TV set in PROTECTED mode. The found error code is indicated by the red LED. The red indicator lamp flashes every 0,3 seconds and stops during 0,7 seconds. The number of flashes depends on the error code (see table below). Error indication Meaning ERROR_1 ERROR_2 ERROR_3 ERROR_4 ERROR_5 ERROR_6 ERROR_7 ERROR_8 Video Processor not responding Vertical Deflection Fault Horizontal Deflection Fault Power Supply Short-circuit. Sound Processor not responding EEPROM not responding Protection hardware not detected Tuner not responding
Error codes 1, 2, 5, 6 and 8 are read via the I2C Bus. Codes 3, 4 and 7 are read through the CTL1, CTL2 and -PD&FAIL signals. Except in codes 5, and 8, the power supply is set in SMPS_B_LOW state.
Protect mode inhibition
In order to facilitate the TV set repair it is possible to disable the protect mode. By pushing the M key (PL100) in a fault detection situation, the microprocessor resumes normal execution flow except in ERROR_4 state (Power Supply Short-circuit). In this case the microprocessor keeps the power supply in SMPS_B_LOW state (the M key does not act).
Power supply repair procedure
* When it is necessary to replace the IC800, it is strongly recommended to replace also the current sensor resistors R804 and R805 (they may be also damaged or altered). * Keep in mind that when the power supply is forced to SMPS_B_HIGH state and without current consumption at the main output (deflection stopped), B6 is the stabilised output. The minimum voltage circuit is working and B6 can go down from the nominal 10 volts to 7,5 volts approximately.
Non-volatile memory (NVM) replacement, IC125
When the TV set starts up, the microprocessor checks the non volatile memory in order to know if it has been properly initialised. Even if it detects no initialisation it will continue the start up procedure with a minimum default adjustment values stored in ROM. Then, in case of NVM replacement, it is necessary to initialise the non volatile memory from the SERVICE menu (it will load a complete set of default values) and �reboot� the set in order to refresh all the settings. After, it is necessary to fine tune all the parameters to its correct value.
