Home-based smart televisions can be used for some time with such small problems, some of which can be repaired by themselves and sold without knowledge. This post is a summary of the experience of the tv maintenance staff and is worth collecting
I. Discretion determination:
It's the first step to learn how to figure out which part of the lcd is malfunctioning.
1: there's no sound on the switch, the light flashes, and the screen flashes white light in the flash. This failure is mostly caused by backlight panel damage. But it was also encountered in maintenance that the lamp was damaged inside the screen.
2: a back-to-back screen shows up. Sound is normal. The first thing that happens is bad digital plates. The second is bad internal contact.
3: turn on three, power lights are not on. The first is power panel failure, the second is cpu part not working properly.
4: light flashes cannot turn on: cpu bus is not working properly or ic (bios) is not working well, contact between "bios" ic and cpu is not good
Ii. The idea of maintenance:
1. Powerlessness of the monitor as a whole
(1) power failure:
This is a very simple malfunction, which is more common outside of the ordinary lcd extension, both in-house and off-site. Regardless of the power source, its structure is much simpler than that of the crt monitor, and it is generally vulnerable to small components, such as a safety tube, a current bridge. 300v filtering, a power switch, a power management ic, a current output diode, filtering, electricity. The ic: 6841,203d06 is commonly used for power panels, and these commonly used pmw chips are available in specialized lcd stores like mine。
(2) drive failure:
Driver burn insurance or pressure chip failure, some of which is internalizing the switch and exporting two sets of power, one of which is 5v for signal processing, and the other 12v for high voltage plate backlighting, which may cause both sets of power to fail. First check 12v pressure normal or not, followed by 5v voltage normal, since the cmu chip of a/d drive is working at 5v, so when failure is not detected, 5v volts are measured in 10,000, without which 5v or 5v volt pressure has become low.
Another possibility is that the load of the 5vs has increased, the 5vs has been pulled down very low, in other words, the later signal-processing circuits have been damaged, some of the circuits have been damaged and the load has increased, the 5vs have been pulled down very low, one line of faulty elements has been checked, the 5vs have been replaced with the faulty components, and the problem can return to normal, which is often resolved, as the cmus are often unable to open when the 5vs have returned to normal, for a number of reasons as well, on the one hand, the mmu process has been washed away, which may result in the failure to open the machine, and on the other hand, the mmu itself has been damaged, for example, by the i/o of the mmu, which has been unable to scan the keys, and the problem of finding hardware is not working, even if you have to change the mcus, because we can only use the generic a/d drive plates to replace them: 151d or 161b.
2. The screens will not be lighted, but the power lights will always be green。
This problem is usually caused by high-pressure abnormalities, which protect circuits, in which case there is a display on the general liquid crystal screen and the way to look at it is "slash."。
3. Display black screen, no backlight. Power lights are always on.
Italical crystal screens have display images, mostly of high-voltage plate power circuits. Focus on checking the normality of the 12v power supply (fibre f) and 3v or 5v switch voltages. If the failure to output is caused by the mcu problem switch control voltage control (aic1084) 3. 3v instead of ... The idea of repairing the high-voltage plate (power fuse - switch control) - ic - push-off large-power switch - da conversion circuit (energy perception, current piping) - - - lc-voltage circuit (pressor transformer, voltage shield) - - calibration-light.
4. Screen light, flash belt or dark line
The problem is usually the failure of the liquid crystal screen。
Lightline failure is usually a problem with the line line that connects the liquid crystal screen body or an i. C. Damage caused by a line or column.
The dark line is typically a screen with a leak or a tab flexible plate to open the circuit. The two problems are basically death sentences for machines, not maintenance, because a screen is too expensive. High
Got it。
5. A screen or white screen
The problem is usually a problem with the screen's drive voltage, starting with the switchboard and screen-wire test, or failing to check the backboard power circuit, repair the idea: drive plate 5v to the pressure block of 3. 3v (aic1084)
Whether there is an electrical output ... - screen drive fuse (f) - 3. 3 v - - dc-dc conversion circuit - negative pressure to form ic(-7v) rows, column driven ic.
Aat1101a m150xn05 screen power management chip, damaged and shown as white screen'turn on
Aat1164 m170eg01 new screen-up disease, mainly on the miki pp71g+ lcd monitor. It's a white screen, it's off, it's on, it's on, it's high
Pressure generation and management of chips, frequent failure of the crystal display, failure of white screen。
6. Colour bias
The plant adjustment model is generally accessible. In the absence of this model, maintenance thought: replace screen and switchboard - - rewrite driver - drive plate bad (unusual) - control of backboard
Ic-made (unusual) - remove screens to observe backlight colours (backlights are old) - change lamps.
7. Character fiction or tail drag
Maintenance thought: check the vga signal line and focus on whether the surface line of the r. G. B three-colour line is connected properly - - replace the screen or switchboard - - rewrite the driver - - replace the drive - switchboard - lcd backboard signal interface ic bad - - lcd screen backboard contrasting epoch adjustment - - lcd screen steering panel error - specular error
There are stains inside the lcd screen
Maintenance thought: wipe or replace protective film replacement - - dismantling screen to clean outer optic and organic glass (treated with cotton ball, pure water) - wind cylinder drying
9. Lcd screen leakage or uneven light
Maintenance thinking: re-installation of lamps - adjustment of light board
10: lcd screen highlight
One or two large bright spots that can try to lighten the tip of the finger and disappear, suggesting that multiple pixel switches and electrodes are missing. Snippets
It's dusty. It can be cleaned.
11: low lcd screen brightness
Check for high pressure plate adj brightness circuits -- -- change light tubes -- change pressure plate -- adjust or replace light board
12: error hint "out of frequency"
Check signal lines - rewrite mcu driver - + replace eprom - rewrite eprom program - + change drive
13: backlight on the white screen without pressing the switch when power is activated. Images can be displayed normally when the button is pressed
The switch signal for the high pressure plate interface and the adj signal reverse caused the switch output, which is partly an abnormal one for the drive panel mmu, to rewrite the mmu program for repair.-------------- for cmu
14: to add that the size of the lamp tube is to be removed when changing the old screen of the lamp tube, because, although the size of the screen is the same, the length of the light pipe is slightly different from the size of the thick tube, and if short lamps are not found, if they are not available, the longer tube is carefully removed with a surgical knife and insulated with the thermode。
