One of teeth of the plastic gear wheel, which opens forward and retract the cassette tray, is broken. The tray does not come forward.

The spring that engages the teeth of the freewheel is broken.
The disassembly of the rear hub is not easy.
Look up the instructions for this repair on the manufacturers website for your model.
Allow several hours for this repair.
Special tools are usually required.

The plastic gears on either side of the drive motor have the teeth sheared off. I just have to find somewhere to buy the parts.

If the tray mechanism is belt driven, the belt may have become loose or is broken and needs to be replaced (usually the belts are of a standard measure and can be purchased in electronic stores or via internet), but if there are only gears to drive the tray mechanism then it could be broken teeth on a gear wheel, faulty drive motor or faulty motor driver electronics.

Hope you can fix it.

Regards,

Triarcuate

I have a Sony MHC-GX555 stereo and every time I try to open the disc tray it either flashes EX-Change or mechanical error and it won't open.

The most likely cause is your antennae mast is broken or has stripped its teeth. The mast is sold separately and contains the snake-like gear. The motor must be removed through the right inner fender well. You may have to open up the gear in the motor to get out the broken piece of the snake-like gear,

Try changing the SMPS.

I suggest using Belzona (metal compound). Mix it with its hardner, paste it over the broken gear (dont worry if it gets over a couple of other gears. Let Belzona sink and dry (4-5hours). Get a Dremel drill with a fine blade on it and cut accurately where the teeth are meant to be. Voila, you have fixed your gear.

Somehow the "gears" (side of tray has "teeth/gear" and wheel to the right of it has 'teeth/gear") which guided the cd tray were misaligned. With trepidation and fear of fully breaking it I lined up the tray and large wheeled gear to the right of tray.
At first I could get it to close to a certain point but it wouldn't go any further. I couldn't figure out what was stopping the closure but finally figured out the "teeth/gear needed further alignment.
During the repair found date CD player made was 1986 !!!! So I figured I'd just have to buy a new one. But it works like new and still sounds great
Go figure. Technics is a great brand.
What I saw as a white "wing nut looking" part had nothing to do repair. But during repair part of the front of repair dropped down and prevented closure. But there is a metal wire under tray which can be manipulated to control the piece which drops down.
Don't know how many Technics SLP110 are still out there but that's my story.

Check out this website if you have an outdated machine without a parts program still in place it may come in handy.
http://www.rushgears.com

my dear sir please open the cassetle feeding unit it have two sensors  ,may b there is some dust so please clean it .it is very good copier dont perchase new one it is very small fault only