I had an early (late 80's) Sony portable CD player and as it was nearing the end of it's useful life it would skip to great annoyance. I am an experienced electronics technician and tried all cleaning methods to no avail. In my opinion based on my personal experience, Sony builds products to a limited lifetime specification and once the product is worn out, replacement is the only economical alternative. As you can guess, I replaced it with a different brand. I like Panasonic and Phillips portable audio products. Both of them have since been superceded by the iPod, however. In summary, it's time to replace your CD player.
- Bigguy