Chapter 1 Changhong's new flat-panel color TV bus adjustment
1. 1 Changhong LS12 LCD color TV bus adjustment
Changhong LS12 movement LCD color TV bus system microprocessor and TV small signal output circuit adopts super single chip MST9U88L,
Complete the processing of all analog signals, digital signals and control signals, and complete the frequency with the cooperation of the external 128MB DDR (U11)
Conversion and scan format conversion. The movement uses external FLASH program blocks to execute many instructions, and the communication between CPU and FLASH blocks adopts
In serial mode, the number of pins is reduced and the stability of the whole machine is improved. The audio preamplifier circuit adopts LM358DT;
The sound amplifier circuit adopts TFA9843AJ or TFA9842FJ.
Applicable models: Changhong LT26600, LT32600, LT37600, LT40600, LT42600, LT4219P (L04),
LT4619P (L04), LT47600, LT47588, LT37700, LT42700, LT47700, LT32866, LT37866 and other liquid crystals
Color TV.
1. 1. 1 Bus adjustment method
【Enter/Exit Factory Mode】
Enter the child lock menu item in the main menu in TV mode, and press the "OK" key to call up the password input box. sequence on the remote
"Number 7" key, "Sub-picture image" key, "Number 9" key, "Sub-picture channel -" key, you can enter the factory mode,
Picture 1-1
The upper part of the screen shows the "M" factory menu logo and version number
code, as shown in Figure 1-1.
After the adjustment is completed, the remote control shutdown, the data is stored,
and exit factory mode.
【Item selection and adjustment】
After entering factory mode, the lower part of the screen displays INDEX
and number, the number represents the index number of the current adjustment item,
Under this page, you can switch to different index numbers by pressing the "P + / P - " keys to select adjustment items. Each adjustment item has
The unique index number corresponds to it, the maintenance personnel can directly select the item to be adjusted by pressing the number key according to the index number, and press "P + / P - "
key to sequentially select adjustment items.
After the item is selected, for the analog adjustment item, press the "V + / V - " button on the remote control to adjust the data of the selected item;
For function settings or automatic adjustment items, press the "V + " key to enter, and press the "OK" key to confirm the adjustment, and the adjustment will be carried out automatically.
When the adjustment index number is 2 digits, enter a 2-digit number. For example, when adjusting the white balance, press the number "4" key, you can
See that the index number turns green, and then press the "OK" key, the index number turns red, indicating that the corresponding white balance adjustment has been selected.
whole project. To adjust the reproducibility, enter "3" and then "2" to adjust the reproducibility.
【ADC AUTO automatic calibration】
In order to meet the normal color display of the received YPbPr and PC signals, it needs to be carried out in the YPbPr and PC state. Prepare PC, high
Clear each signal source, input the full-color bar signal (COL-SMPTE of FLUKE 54200) under YPbPr and execute the
ADCAUTO. Input black and white window signal under PC for automatic color correction. The signal can be controlled by software DMW under PC
Generated, the image is similar to the grayscale picture signal.