Audio Systems: CD detection switch, circuit board assembly, photo transistor

Question
Tom, I have extracted the CD player unit form the Mitsubushi stereo unit, and am searching for the CD detection switch. I'm trying to use some deductive reasoning to find it. I have found a series of moving gears that move into position in order to depress a PCB-mounted "button" -- is this the CD detect switch? If so, do you recommend any partuclar retail or online-retail aftermarket electronic parts suppliers? I don't see a model number on the switch, just the letters OP (and on the circuit board, the label "SW801".)
If I'm on the wrong track altogether, then I'm feeling clueless, as I don't see any circuit board located on the top of the CD deck assembly, only below.

Thanks in advance for any more advice!!!
Charles

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Followup To
Question -
I've had an issue similar to a recently posted topic -- a 'whirring' or buzzing sound (for a few seconds) when power is applied to my Inifinity CD/Radio/Cassette player. CD's are not accepted into the unit.  I had the same problem professionally worked on a couple of years ago -- looking at the old invoice, it reads "replace CD detect switch". This work cost me about $150.00. Do you think it's at all possibe that this is something that I could do myself, and how readily accessible is a new part? OR could it be something else?  THANKS!
Answer -
Charles,
The CD detection/in switch is a photo transistor that fails on many CD players. An after market detect switch/IC can be purchased from most electronic parts suppliers if you can read the numbers on the original part. The detector board is located on the top of the CD deck assembly.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net


Answer
Charles,
On some models of CD players the CD in or detect switch is located on the lower circuit board assembly. When you insert a CD the infrared LED will reflect off the CD to operate the detect in photo transistor which will give the controller a load in signal to turn on the load motor.Once you locate the load in detect unit you can use a volt meter to see if the output of the detect switch changes when a CD is inserted in the CD slot. If the output voltage does not change when you insert a CD, the detect in unit is defective, if the voltage changes some trouble shooting of the load circuits will be needed.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net