I am about to open up several faulty music cd players (protable and small kitchen type stereos). They all seem to have a similar problem, the "signs and symptoms", as it were, are very similar, and all of the units just seemed to have died of old age; i.e., they never sustained any trauma or damage.
When you put the CD in, the base motor rotates for a while and the other motor moves the laser diode up and down a couple of times before failing to establish a connection, and eventually it eventually gives up. Some units display "error", some display "no disk", some just turn off.
While the CD is spinning, you can even skip through the tracks, but the system is never able to lock on to the selected track.
In my opinion, there is nothing wrong with the control electronics or the processing side, but that the problem lies either with the motor(s) or with the optics.
When repairing old equipment one of the first things I look at is the electrolytics near heat sources like power transistors. Nearly every TV I have fixed had failed due to a "dried out" cap.
My understanding of electrolytic caps is that they have a mean life expectancy of 10-12 years, which makes capacitors a legitimate concern. Hence, sometimes people just recap an old board without too much investigating. However, I am not convinced it is the capacitors, because the problem seems to by the same for each unit (so then why that same capacitor when these devices are low powered and don't get that hot?).
I have looked on the internet for some clues, but I didn't find anything of substance. It seams most people just throw away their old CD players and buy a new one (I use an MP3 anyway, so please don't suggest buying one as an answer). I could quite easily throw them in the bin and forget about them, but then I would still be left in ignorance about this problem.
My reasoning tends towards the diode or phototransistor having deteriorated over time, so a disk is detected but the system effectively behaves like the CD is scratched or dirty (which is not the case having tried with multiple CDs - obviously).
What is the best way of testing my theory (the diodes), without an oscilloscope? I have some old working CD-ROM drives and could possibly exchange the diodes, but I was wondering if there was a better way, since it may not be the diodes at all, maybe the motor or driver circuit.
What do people think?
.o:0|O|0:o.
P.s. Someone once suggested that the expiry date is built into the system (like the Blade Runner movie), but I think that is unlikely, though technically possible.