LCD display Huaping Troubleshooting
2012-08-26 by seoer10
Failure phenomenon: the beginning of the year a friend replaced a 15-inch LCD display, model is AOC LM-500, has been using the normal. But just six months, this LCD
Indicator that a fault occurs, specific performance: as long as the computer is started or restarted, it will approximate "Huaping failure phenomenon, gives the impression as if the high-frequency electromagnetic
Interference, as the writing on the screen is very blurry and jagged. Into Win98SE system occasionally this failure phenomenon but the duration is very short and does not
Too obvious, most of the time the screen display is normal.
A digital interface, and VGA interface is connected through the internal digital / analog converter circuit and graphics. This form of connection, although it solved the the signal matching problem, but are also with
Come susceptible to interference and distortion. The reason, mainly because the liquid crystal display clock frequency is difficult and the input analog signal of the clock frequency is maintained
Synchronization, especially in the analog synchronizing signal frequency changing, if the synchronizing circuit of a liquid crystal display, or with the graphics synchronizing signal connection
The transmission line short-circuit, poor contact and other issues, unable to adjust to the follow-up in order to maintain the necessary synchronization between, there will be the start encountered
Abnormalities, and enter the system and then display the normal strange fault phenomenon.
I will check the focus on the adjustable connector pins, transmission cables, as well as synchronization circuit components above.
Through the case, did not find any open circuit, short-circuit and physical connection issues. Next, along the line direction of the cable connection, the input control circuit of the printed circuit board unit found found
Two miniature semi-adjustable potentiometer is mounted on the side of the circuit block of the 14-pin package, a printed circuit board is marked as WR604 other is WR1201. Author
Preliminary judgment according to previous maintenance experience in CRT monitors, two miniature semi-adjustable potentiometer, is probably used to synchronize the fine-tuning, but in the end what a problem it?
In order to secure and reduce the the number of disassembly LCD shell, I use anhydrous alcohol to two-and-a-half adjustable potentiometer all the cleaning, wipe it again until the alcohol all volatile
After the LCD monitor housing recovery power test machine and found that although the fault has been reduced, but several times in a row during the boot process fault sometimes be repeated. Helpless and then a
The times apart the casing of the LCD display, using a mini-Phillips screwdriver WR604-clockwise to adjust a little shell, followed by recovery and once again energized test, the liquid crystal display
The display showed normal this point, troubleshooting.
Consider the fundamental solution, or replacement of a semi-adjustable potentiometer. Unfortunately, this is a big deal than mung bean how many semi-adjustable potentiometer in ordinary electronic market is difficult
Buy, I also have not succeeded.