How to determine if the camera lenses lens needs to be replaced?

The main criteria for determining whether the camera lenses lens needs to be replaced are as follows:
Physical damage inspection
Firstly, observe whether there are scratches, cracks, or damages on the surface of the lens, especially in the front and rear lens areas. If there are obvious scratches or broken glass, it needs to be replaced immediately.  ‌
Imaging Quality Assessment
Focusing test: If there is jamming or abnormal noise during manual focusing, or if the autofocus mode cannot accurately focus, it indicates internal component failure.  ‌
Optical performance: Internal mold, fogging, or detachment of lens coating can cause blurry imaging and require professional testing.  ‌
Anti shake function: If the anti shake component is damaged and causes the image to shake during shooting, the lens needs to be replaced.  ‌
function test
Zoom test: If there is stuttering, abnormal noise or inability to zoom during the zoom process, it may involve motor failure.  ‌
Cable inspection: If the camera reports an error after the lens is installed, it may be due to a broken cable or poor contact.  ‌
Repair suggestions
When the lens is affected by moisture, water or mold inside, it needs to be disassembled and dried. It is recommended to have a professional organization handle such repairs.  ‌
If the above issues cannot be judged by oneself, it is recommended to bring the equipment to the brand's after-sales or professional repair point for testing.  ‌