Hi,

Try using a commercially available lens cleaner - example only and see if this works.

There may be something on the lens that prevents a good pickup off the disc.

Alternatively if you wish to clean the lens yourself, here’s a link to the ifixit Samsung BD-F7500 Blu-ray Player Disc Reader Replacement guide.

At Step.7 in the guide the lens is shown in the image (just below the red box). Use a Q-Tip moistened with 90%+ Isopropyl Alcohol to gently clean the lens