LCD maintenance entry: saying that there is no technical content to replace the main chip - android - Phones Developers

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The replacement of the main chip of the LCD motherboard is the ultimate fault. Fortunately, today's LCDs are streamlined and basically "microcontrollers". For our maintenance, the fault judgment is also easy. There is no technical content pure operation, but there is no replacement or no tools. There are a lot of masters who know. Look at the mystery.
tool:
My hot air gun is the first domestic brand of crack, hot air gun for SMD patch is very personally considered very important. This is more than 400 years, a good brand temperature is unstable and hot heart is easy to burn hot heart 40 yuan ordinary miscellaneous brand 60w 936 Temperature control soldering station, good heat temperature, good tip, soldering iron, dragging weapon, high temperature, not easy to burn, durable, I also prefer the quick brand, 15 yuan, daily maintenance, can use 2-3 years, noisy, 5 yuan, no Love ordinary BGA with solder paste instead of rosin are almost not stinky on this 8 yuan without paying attention to the precision of the scorpion, this does not say my ten yuan, 5 yuan also have good goods anyway, do not vigorously make do
10 times small magnifying glass to wash the water (Tian Na water can be replaced)
Here is the picture
I am more violent, the wind is basically the biggest. This chip has a lot of temperature and needs to be higher than 400 degrees.
There is a heat sink on the bottom of the chip. The grounding of the heat sink must be done first with a tin knife or with a tin strip. The pad should be treated with a clean tin strip to handle the flat (I can make it happen. I don't have a tin strip to see the chip center is the knife flat). Absolutely the flat brush hand touch must be smooth and no protruding tin chip to be positioned to be free to move smoothly or not accurate Counterpoint (note that if the tip is damaged, it should be replaced to avoid dragging the pcb pad due to small loss)
After aligning the soldering chip to the foot, simply fix the tweezer and press the chip center heat gun evenly and slowly swing the heating chip center heat conduction melt the belly heat sink to complete the welding for about 25 seconds ]

After the heat sink is fixed, if the alignment is accurate, the welding should be very easy and pleasant. If the alignment is not accurate enough, it is impossible to separate the tin. It is the beginning of the nightmare. It may be necessary to re-heat the wind to remove the money from the beginning.

The final inspection step is: take a scorpion tip or sharp object under the magnifying glass to maintain a certain strength all the way across the chip foot. If the poorly welded foot will be displaced under the magnifying glass, it will be very clear and re-dial the foot and then repair the welding ~ ~ the last few feet Tin together
1 Can be tinned with tin flux to separate tin 2 tin strip 3 soldering iron clean tin edge plus solder Bao tin will flow to the iron tip to separate the tin above 3 kinds of I have omitted the use of gravity when welding The board is evenly fed to the soldering all the way. The flux in the tin is not burned before it is dried. Only the above steps can be processed. The soldering iron is clean and the surface tension of the liquid is used. Gravitational tin will flow to the soldering iron to separate the tin


Here should be used on the blade, tin is not rubbish tin. There is a heat sink on the chip. The grounding soldering chip is necessary for the simple fixing step of the foot. If the grounding is bad, the pcb and the heat sinking are not good. The heat is not released for a long time. It is an ordinary non-heat sink chip soldering chip. The step of fixing the foot to the foot can be omitted. If it is a normal foot, a small chip like a DVD, together with a tin strip processing step can omit the drag welding to complete the soldering and also the meaning is that the hot air gun is removed. The treatment does not deal with the residual tin coating welding treasure directly take the new chip and then the hot air gun scorpion alignment hot air tin melted the chip needs to take the tweezers before and after the left and right to move the purpose is to let the solder more adequate temperature, the chip will automatically due to the surface tension of the liquid In the back position, you can use the tin to pick up the soldering iron and cut off the soldering iron. Dvd chip is removed and replaced by a master in 2 minutes to complete my stupid 3 minutes. This example chip more than 10 minutes