My CD ROM was having trouble reading CD's for a while, and hardly ever got better after cleaning, so after a bit of poking around in it, I found a little circuit with a tiny 'pot' situated on the lens mounting, it was connected directly to the laser diode, so I gave it a twiddle to increase the diode output and my CD works fine now. I just wondered what the pot is called in this circuit? (like LD-gain or something).
I'm asking this because it appears to be an overlooked problem with a very easy solution. My friends CD player stopped reading all CD's and they sent it away to be fixed a total of 3 times, each time it was sent back the repairman saying "It's working fine.". In the end he gave it me to strip down, but instead I had a look to see if I could find the problem. Even without using any test equipment, I located this potential devider and gave it a twiddle. I now have a fully working music system! If it's happened to me twice, how many other people has it happened to? There must be hundreds if not thousands of discarded CD-ROMS all because of a miss-set pot.