Remember to check the cables!

Hi Readers to of Fixya,
This entry is January 22, 2016.
I own a Denon PMA 735R which I bought new in 1999, it is very good Amp; starting about a few years ago the input selector would occasionally randomly jump from CD to Phono to Tape etc., but would always end up back at CD so it was not terribly annoying until a few days ago when it started happening all the time. I am a very knowledgeable electronics person (I built musical keyboards at one time) so my thought was just that it was a dust problem and I started with that premise. I fixed it using an Electrical Parts Cleaner spray and here is how I did it:
I unplugged it, removed the CD input RCA cables and removed the L & R speaker cables and took it off its shelf and set it on a towel on my soft sofa; I removed the casing by unscrewing four big silver screws on the sides (my model is silver) and the three small black screws on the back top; I removed the Input Selector indicator knob on the front and the Record Out Selector indicator knob and the Volume knob, I then removed the small nut that holds the three of them tightly in place to the front panel; I then stood it on its back so that the front was facing up; I then sprayed my Electrical Parts Cleaner spray into the Input Selector indicator post liberally and then put the knob back in place and kept turning the indicator back and forth for a few minutes to work the cleaner inside the post down into the circuit board connection; I did the same with the Record Out Selector indicator post and I did the same with the Volume post; I then put the small nuts back on the three posts and tightened them; I then put the knobs back on the three posts; I then stood it back on its normal upright position and put the casing back on and then the screws; I placed back on its shelf and hooked up the cables and switched it back on and played my CD's, it has been working perfectly fine. The whole process took less than 30 minutes.I hope this helps.

If you take a plastic spoon and press on the "Thingy" it should click when you press it and again when you release it

If it does not do that, the micro switch is goosed and needs replacing

if it sounds like it wants to but doesnt, like you can hear the motor but it is locked up, here is a way to fix it.look at seat and see if it looks sort of cocked and you may have to straighten the seat by keeping rod in one side or other and spinning it until seat is straight. there are 2 flexy cables that run side to side and cause the seat to move. they usually have a black plastic coating on them.remove them both. with both off hit switch and see if you hear the motors.If so you should lubricate tracks with silicone spray or spray grease.put cables back into holes and it should work.the cable may give you a lil trouble coming out but just pull back and forth they wont break

Open your laptop case(Not LCD case) & see the mechanical portion is damaged. IF possible change this parts by byeing secondhand parts from scrap area/ put some synthetic(Do not use petrolium gum) gum & plastic & finish it properly. I think IF you can make it properly it could solve your problem.

I have just fixed my stroller which had a similar problem. The wheel was still swivelling but it was sticking slightly. I noticed that the pin that locks the wheel in place was half out and therefore the wheel was getting caught on it. I undid the nut that holds the end of the wheel lock cable in place and tightened this as tight as I could which pulls the pin back into place (making sure that the switch is in swivel position). I then put the washer and nut back on (making sure cable was as tight as possible).