I'm not sure if this is the right place for this question, but this site has been very helpful with other questions, so here goes. I recently modded my dvd drive (voided the warranty too, I know) and I was wondering if anyone knows of a way that I can connect an LED inside the drive that lights up whenever there is a cd/dvd in the tray (to illuminate the spinning disc)? I am fairly new to electronics but I understand basic instructions. Where would I need to connect the leads (on the drive's board or somewhere else)? Assuming that I use a 3.5~5v LED what resistors would I need?

It's going to be really tough for anybody to answer. What' the interface? SATA, PATA etc. Make and model of drive? Can you find an online manual?

I suspect it will be extremely difficult. One way might be to detect whether the motor is running.

I have another way that might work. Monitor the current in the 12 V supply. When it exceeds a certain value assume the disk is spinning. That may not be too hard.

A design using this http://focus.ti.com/lit/ds/symlink/ina168.pdf and a comparitor IC should work.

But In this case, the LED would light while the disc is spinning rather than inserted.

Sorry, it's an HP dvd1040 with PATA interface. I haven't looked for a manual, but I will. Honestly, it doesn't matter one way or the other when the LED lights up (with the disc in or spinning). If it was lit up anytime there was a disc in the tray, that would be fine too. Any suggestions?

Did you ckeck your PM's (Private Messages)?

Were you thinking of a standard LED or a LED like the Rebel series from here:

Luxeon Rebel compact smd LED. Color bin VO; flux bin Q (http://www.theledlight.com/luxeon-rebel.html)

Phillps apparently has an evaluation board. These LEDS are really bright and may require a driving boad. I didn't check them out, They do require a heat sink.

What else is important is how power is suppled to the drive. The PATA power connector or the Molex connector.