1. Check whether the lens is contaminated.
2. First put the white paper under the cutting head and observe if the red light is round and the middle is relatively clean, it proves that there is no problem with the red light and there is no problem with the lens. It is obvious that there is an obvious black spot in the middle of the red light, which proves that the protective lens is dirty and it is necessary to replace the protective lens.
3. Check whether the light is defective.
Use dimmable photo paper. The distance between the photo paper and the cutting head is about 40 centimeters. Adjust the power to 100% and perform burst shooting while blowing air. Normally within 30 milliseconds. There are so many black spots on the lens, and there is a particularly big one in the middle. You can tell that the lens is dirty at a glance.