Changhong rear projection TV DP4388 convergence adjustment method - android - Phones Developers

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Changhong rear projection TV DP4388 type rear projection color TV convergence adjustment method 1, the convergence is poor.
Adjustment method: the poor convergence of the rear-projection color TV directly causes the image on the TV screen to be distorted. The image may have geometric distortion, other contours of the screen with other colors, and the screen display is disordered. At this time, the convergence state can be seen. The convergence of the red, green and blue convergence lines can be seen. Not coincident, and there is geometric distortion. The reasons for poor convergence are deterioration of component performance in the convergence component, failure of the convergence power amplifier circuit, and changes in the installation positions of the three projection tubes due to transportation, moving, and the like.
The above three reasons can be determined by the following methods. In the convergence state, adjust the convergence of the horizontal, vertical directions of the R, G, and B convergence screens to see if the debugging is effective. If one or several channels of convergence are effective, the working voltage of the convergence component, the bus signal, the main line synchronization signal, and the power supply voltage of the convergence amplifier (+25V, -25V) are normal. If several of the six-way signals or one-way convergence adjustment does not work, it indicates that there are faults in the several or one-way convergence signal channel circuits. Check that the components of the convergence assembly are soldered properly; pull out the printed board to measure the power amplifier pin ground resistance, and replace the convergence assembly and the convergence amplifier block. If the convergence debugging does not work at all, it can be determined that the convergence component, the external circuit of the convergence component or the convergence power amplifier and the power supply voltage are abnormal. When measuring the working voltage of the convergence component, the I2C bus signal, the line sync signal and the working voltage of the convergence amplifier, etc., the convergence component needs to be replaced, and the convergence power amplifier and the external circuit of the pin are checked, and the fault can be eliminated.
Second, the gathering will be chaotic.
Adjustment method: The function of the digital convergence circuit is to ensure the convergence adjustment of any point, line and surface of the grating. The convergence adjustment is related to the signal system, and the system is different (such as TV-PAL/NTSC, DVD-PAL, NTSC, VGAT, etc.), and the convergence signal adjustment process is different. Only when the signal source convergence adjustment under different standards is completed can the various signal sources connected can be displayed normally. Convergence adjustment should follow the first green square tube convergence grid screen, and as a benchmark, then red and blue projector tube convergence grid screen debugging. After the red convergence is completed, the red and green convergence squares are displayed at the same time. By repeatedly adjusting the red convergence points and lines, a red and green red convergence grid screen is displayed on the screen, indicating that the screen has been displayed. Completed the red convergence adjustment. Then, the blue convergence is coarsely adjusted, and the blue convergence is finished, and then the blue and green convergence are adjusted. When a cyan convergence screen is displayed on the screen, it indicates that the blue convergence adjustment is completed. After the above adjustment, the convergence and fine adjustment process is followed. By repeatedly adjusting the red, green and blue displayed on the screen, only a part of the red, blue, green dots and lines in the majority of the places have overlapped. When the convergence is fine-tuned, the edge debugging of the screen is difficult. It is also necessary to return to the convergence and coarse adjustment state by debugging the convergence screen tilt, the center of the screen, etc., and then return to the fine adjustment state for repeated debugging, and finally a white convergence party is displayed on the screen. Screen. Sometimes it is necessary to slow down the cursor speed when debugging the corners and edges of the convergence screen. The speed of the cursor is usually set to be faster when the coarse adjustment is made, and the cursor speed can be set slower when the convergence is fine-tuned (especially when the adjustment is made). Through the above operation, the convergence adjustment under a standard signal is completed.
Convergence and debugging process is more complicated. When performing convergence and debugging, you can't just press the button of the remote control. Otherwise, the color TV may not display the serious consequences of the TV screen.