
Factor 1: The double protective lenses are damaged.
Solution: Check the lenses under the light to see if there are any stains. If yes, the protective lenses need to be replaced.
Factor 2: The light transmittance of the protective lens is not enough or the coating is not resistant to high temperature.
Solution: Replace the protective lens with a high-temperature resistant and light-transmitting one(video).
Factor 3: The center point of the red light deviates and hits the inner wall of the gun body.
Solution: If the red light is biased to the left or right. Adjust the center offset function from fiber laser welding machine system parameters. If it is biased up or down, then the motor needs to be adjusted.

Factor 4: The focus lens is damaged.
Solution: Replace the focus lens of the handheld laser welding machine(video) .