Hi,

I can only suggest that if the CD head is not working that you open up the unit and wipe the lens “gently” of dust.
If it cannot focus it won’t read the disc and skip into a hunting mode. It shuts down, as if on strike (:) and puts out a read error code.

Sometimes a no disc code even comes up but that’s can be a little deeper issue than just cleaning a lens.
The rubber supports can break or the arm jams and does not travel.
Most cases the lens is mounted in a plate or arm that traverses across the disc.
It is meant to float float over the CD in the air current above the disc.

All this Subdues vibrations and jostling of the car.
I have substituted tiny o rings in some units because of one being rotten or too hard and the lens was being cocked out of focal range.

If the unit doesn’t work you got nothing to lose.
Gaining some experience on how things work, for nearly free, is a real commodity nowadays.
This way you get one more valuable payback out of it that you build on to fix other things.

Knowledge is an accumulation of experiences. If we got all we needed to know in one shot in our beginnings, there would be no need to explore, as there would be no unknowns. (:)

Phil