There is a light notebook specially used to provide the brightness of the screen, but there are a lot of users often reaction notebook screen becomes more and more dark, so easy to users of the visual impact, through the following ways to solve the problem of dark screen.
Failure cause
1, tube off (generally normal use computer won't because of high voltage burned or disconnect tube, tube open main reason is: the computer fell to the ground and lamp knocked serious)
2, ignition coil no electricity to light tube (motherboard have 3-4 groups voltage for the ignition coil, ignition coil after chip after transformer for the tube, the chip aging or high current the chip is burnt out no electricity output)
3, mainboard no electricity to the ignition coil (motherboard have 3-4 groups voltage for the ignition coil, motherboard have two groups chip output voltage to the inverter, the chip aging or high current the chip is burnt out no electricity output)
4, power solutions, or display set problem
5, connecting line disconnect between mainboard and ignition coil has a root connecting wire connection, long time move LCD connecting wire break, causing no main electricity to the ignition coil)
Above 5 points are caused by the screen dark main problem point, the first 4 person appear more, 5 point appear less opportunity, because the connecting line is to use a special kind of shielded wire covered the and less likely connecting wire break phenomenon. For professional maintenance staff testing each process is indispensable. The following is the author in the test process found a special example.
Add: case analysis
The notebook screen partial dark fault phenomenon
With customers to understand in the evening when the use of the computer screen after resting on a dark again
The notebook screen partial dark fault basic detection
Meet this situation the first one to do is external PC display to see if can enter the WINDOWS external is normal display. This step is very important, software and hardware can be determined whether there are other problems do a very good observation. Determine the system correct, then the author (had better ask professional notebook maintenance teacher to check, had better not privately apart) then open screen, will see HIGH dangerous board (HIGH VOLTAGE) this is inverter, the inverter insulated taken away, we can find the inverter, the structure of the main board have 4 lines and inverter connection, inverter through the chip distribution VOLTAGE to coil, the coil VOLTAGE booster lighten the supply.
The notebook screen partial dark specific inspection and maintenance
1, the author first use substitution method replacement lamp test tube is disconnected, the inverter on the tube interface from the inverter and out, on the pre-arranged on tube boot however no reflect, eliminate tube.
2, the main board to test whether there is 3-4 groups above voltage for the inverter, the inverter main board connected to the interface and using a multimeter test voltage (usually if maintenance company have the same type of DV4-2145DX LCD Screen Inverter can through the substitution method change inverter testing, but the author does not suggest that we do this, if the problem is caused by the motherboard screen partial dark, make good inverter mount are likely to good inverter also burned, so in the process of testing the best is to put the whole voltage test all good no problem rear can make good inverter replacement)
3, the host has two hole position, only in hard gently outward toggle can get out, get open, we can see the main board and inverter connection port, we continue to use multimeter test connection port position power supply is normal, strange things will happen at this time, the motherboard even outlet voltage is normal, how to another terminal voltage didn't.
4, then the author put cover screen shaft cap and go see the location of the turning of the connecting line have rolled into a ball, preliminary suspect because long time swing screen and off line. We put the connections on the mainboard and out from measuring whether ends connected.
5, the connecting line and after coming out, we can see the shielded wire has been cracked, shielded wire are apart after that there are three line is off, the author found that interconnects have welding, now once again open reason might be because often snap screen rotation and the connecting wire broken, or before the welding didn't put the connecting line extension shielding bad so often snap and the connecting line broken.
6, problems found and then the author find 3 thread off part of the extended welding is good, use the shielded wire wrapped all the line after put back on in situ, tube display finally to normal.
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