Problems prone to Face ID:
1. The dot matrix projector is damaged, short-circuited when changing the screen
2. The red dot does not flash.
3. Be careful when disassembling the screen, the long ribbon cable is easy to be damaged when you pry it open.
4. Detect with iFace dot-matrix detector and display the fuse.
5. Use the Luban tool dot-matrix repairer to untie.
How to replace the chip under the dot matrix:
1. Separate encrypted small board and prism:
a. Tear off the protective tape,
b. Cut half of the solder joint with a sanding pen,
c. After jamming with the clamp, use a blade to pry open a little, and not to deform the iron cover
d. Pull out flat, the prism should not be stained with dust
2. Replace the encryption chip:
a. Stuck the encryption board, shovel the power supply pipe, capacitor, and encryption chip,
b. The encryption chip (two layers), capacitors, and power supply tubes are replaced by inductors with medium temperature soldering.
c. Check whether the dot matrix works normally after repairing and whether the red flashes.
3. Install the encryption board and prism.
a. Insert it to make sure the position is aligned.
b. Install the sponge and make the fixture stuck.
c. Put glue on the side circle, like B7000 glue.
d. Determine if it is sealed.
4. Install the machine, enter the face, and observe whether the dot matrix is working properly.
5. Restart and test again.