onkyo dx7210 cd player..gear problem

roonie

Member
2010-02-07 4:05 am
Hello...im not much of a stereo fixer but can fix almost anything else.
i hook up this used onkyo dx-7210 cd player and get this gear slipping sound so take it apart and find it is in fact two gears not meshing. I find this youtube video and this guy has the EXACT same gear problem. The issue is i cannot tell how he fixed the gears because its not in english. I tried for hrs. to translate the video to english with no luck. Im hoping somone on here can tell from the video what this man did to fix the gear problem. I can visually tell that the gears are not tight together when it cycles. Your help in this matter would be greatly appreciated. thank you
YouTube
 

ubergeeknz

Member
2018-08-31 12:32 pm
The switch shown at 6:29 is meant to detect end of travel for the laser. He takes the cover off and I expect cleans the contacts up and reassembles the switch. Then it correctly senses end of travel (note 0.02 ohm reading with mechanism reassembled at end stop position) and stops trying to move the laser past the end of travel.
 

roonie

Member
2010-02-07 4:05 am
hi...thanks for all the quick replies folks. The teeth on my gears seem fine. What appears to be happening is , the male shaft on the white wheel in mention, is a bit wobbly inside the female hole that it sits in. When i pull the gear out, the eye reader slides nice and freely.
I am wondering if there is a way to tighten up this free bore space of the white wheel shaft so that the gears stay meshed? While in the video it shows the guy cleaning the rails etc. i doubt that it fixed the problem. Maybe he replaced the white gear but doesnt show it being replaced as the video is edited in places. So i have two questions,,........
1) is there a way to tighten this free bore in the shaft hole or on the white wheel shaft?
2) is there a replacement white gear available for this unit? Its labeled 1995 on the back of the unit. Its actually very clean inside this unit and the white gear looks like no wear with grease still present on the shaft.
thanks again for the quick replies. I may soon forget how to get er back together...lol
 

roonie

Member
2010-02-07 4:05 am
Are the teeth and the sprung two part rack on the actual pickup OK?

Its very hard to advise on things like this without actually having it in front of you :)


yes...the teeth are fine. If you watch the above video ive provided, that is exactly what is happening to mine. I am trying to figure out from the video, how the guy in the video fixed the meshing of the teeth.
It seems the hole that the white wheel sits in has some play..maybe its normal play...i dont know. when the wheel begins to spin, it comes away from the black wheel and buzzes, skips...teeth look fine. pls watch video and...ARE PARTS STILL AVAILABLE FOR THIS 1995 UNIT?
 
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roonie

Member
2010-02-07 4:05 am
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roonie

Member
2010-02-07 4:05 am
here it is. I can, with my finger, push light pressure on the white gear and it will pull away from the black gear. Its almost like the white gear wheel has a weak axle or weak area where the flat part of the wheel forms onto its own shaft IMG_20200203_193540.jpg IMG_20200203_193327.jpg
 

roonie

Member
2010-02-07 4:05 am
the white wheel/gear with shaft slides down into a hole and is driven by a motor that is driving the black wheel/gear
the white wheel/gear has a split at bottom that holds the shaft into the hole...pinch the split and the white wheel/gear pulls out of its hole. There does not appear to any where on anything. It just seems the white wheel/gear is made cheaply and is flimsy. Im thinking maybe epoxy a quarter or a metal washer on top the white wheel/gear to strengthen it. The shaft has a hole down the middle of the center.
 

Mooly

Administrator
Paid Member
2007-09-15 8:14 am
Some of these nylon gears (speaking generally) can be very flexible and bendy. Have you looked at the black gear to see if that could be moved at all. Are all the plastic chassis inserts (the black moulded plastic inserts) OK and not split of damaged and so causing anything to shift.

The chassis will probably be fairly common (Sony?) and you might get a scrap player that uses one very cheaply. You could swap everything over.
 

roonie

Member
2010-02-07 4:05 am
I have checked all of the chassis inserts. Because all of the gears are in great shape i think i will probably run a metal rod (finish nail perhaps) down the inside of the shaft of the white gear and pour some epoxy atop the wheel to beef things up. thanks to all that replied.
 

n0c3k

Member
2021-03-29 9:16 pm
dirty fix

I actually registered just to reply as I was struggling with this for the past 2 weeks.

I'm afraid adding rigidity to the axle may not fix the issue as after watching the mechanism closely I came to the conclusion that is actually the lower narrower section of the white gear that skips making that awful rattling sound. At least in my DX-7210. Here I'd like to note that this is just an observation by a newbie, I've been tinkering with all kinds of electronics for about 20 years now but I've only recently ventured into Hi-Fi territory.

So here's a dirty fix... Teflon Tape.

After cleaning and lubricating everything thoroughly the sound persisted so i figured i would need to improve the "grip" of the gears so I thought of teflon tape. About 3 full circumferences did the job for me.

adding less tape muffled the noise a bit but didn't fix it and adding more just made the gears slide so after several attempts I landed on 3.

I know it's ugly and likely won't last past a couple of months or shorter depending on how frequently you listen to your CD collection but it's way less invasive than modifying the gear in a permanent fashion.

as a side note: Make sure to clean and lubricate inside the two piece rail held together by a spring (to the left of the white gear looking from the front) I missed it the first 3 times i attempted to fix it. :(

hope this helps
 
KSS-213C KSM213CCM Optical Lens Mechanism Replacement for CD VCD Player | eBay


Different Laser (yours is a KSS-240, none on ebay with the 'Mechanism') but the chassis will probably be the same. Certainly the gears will be.

I have never come across failed gears in the way you describe but many times the teeth get worn and don't mesh.
This is often caused by the 'Home Base' Switch being dirty and the sled Motor continues to drive the Laser Home when it is already there and the gears' teeth get worn away.

Clean the Switch contacts ( as I think he does in the video and as someone on this post has already recommended) and change the Gears.
If the Teeth on the actual Laser are worn (very possible) then a new Laser would be needed.

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313&_nkw=kss-240&_sacat=0

P.
 

MAAC0

Member
2010-05-02 10:00 pm
Are the teeth and the sprung two part rack on the actual pickup OK?

Have You lubed them already ? Sometimes the lube gets sticky and the parts don't slide.

I believe the white gear isn't sitting flush on the chassis hole and that's why it shifts.
Put something in the slit (toothpick piece ??) in order to force it open against the hole walls.
Don't force it to much or the tabs will break.
A rod in the center hole could also work.
 
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