Pioneer XR-A670 cd changer mechanical issue

[mike_drz]

Hello all, I've been fixing up an old cd/tape/stereo bookshelf type unit. I cleaned the rail for the laser and greased it all up. That fixed the first issue where it wasn't reading the disc. To my great joy, there's another problem.

The CD clamp rubs against the top assembly, causing the CD not to spin, or make noise if it does. If I push down in the middle of the assembly, then it'll play just fine. I tried bending the plastic, and it'll work for a few minutes. Now it's back to not working.

Am I missing an adjustment anywhere? Is there supposed to be a rubber part at the top of the disk clamp? Maybe something fell off and got lost causing the gap to shrink?

Any help would be appreciated, thanks in advance !

[Chungalin]

Re: Pioneer XR-A670 cd changer mechanical issue

The most common cause of this issue is that the rubber shock absorbers (4, one at each corner of CD mechanism) are decaying. Since it’ll be difficult to find exact replacements, I recommend to add some cardboard supplement below them, in order to elevate the mechanism 1-2mm.

[mike_drz]

Re: Pioneer XR-A670 cd changer mechanical issue

The most common cause of this issue is that the rubber shock absorbers (4, one at each corner of CD mechanism) are decaying. Since it'll be difficult to find exact replacements, I recommend to add some cardboard supplement below them, in order to elevate the mechanism 1-2mm.

Chungalin, that is genius! That never came to my mind at all while looking at it. I will take it apart and give that a try. Thanks so much for your advice

[R_J]

Re: Pioneer XR-A670 cd changer mechanical issue

Another thing to check is the spindle on the motor shaft, they can, over time be pushed down the motor shaft enough to cause the top clamp to rub, sliding the spindle up very slightly can fix this issue

[mike_drz]

Re: Pioneer XR-A670 cd changer mechanical issue

Another thing to check is the spindle on the motor shaft, they can, over time be pushed down the motor shaft enough to cause the top clamp to rub, sliding the spindle up very slightly can fix this issue

RJ, it's been a while. How have you been? That's something else I'm going to check out. I have put it on the back burner for now, as the workbench has a wood working project on it right now.

From what I recall, the spindle looked like it was on a bit of an angle. It's as if the whole assembly is not coming up all the way. It's on a spring from what I see in the service manual. I'll take a look at it soon enough; and let you guys know.

Mike

[R_J]

Re: Pioneer XR-A670 cd changer mechanical issue

It could be that the mechanism is slightly out of alignment, maybe out one tooth causing the cd mech. to not come up fully, or bad drive belt.
Did you have the servo mechanism out and the rubber float feet off? they are different between the rear two and front two, they are usually different colors, if they are backwards the servo mech. will be crooked.
looks like #23 AEB7063 are the front (nearest the spindle motor) they are blue
#24 AEB7066 are the rear, they are black

[mike_drz]

Re: Pioneer XR-A670 cd changer mechanical issue

It could be that the mechanism is slightly out of alignment, maybe out one tooth causing the cd mech. to not come up fully, or bad drive belt.
Did you have the servo mechanism out and the rubber float feet off? they are different between the rear two and front two, they are usually different colors, if they are backwards the servo mech. will be crooked.
looks like #23 AEB7063 are the front (nearest the spindle motor) they are blue
#24 AEB7066 are the rear, they are black

It looks like a combination of things causing the problem. I took the mechanism apart for the first time. The black rubber floats are chalky in colour. I took them all out, and sprayed them with some silicon spray. The motor shaft does have some vertical play on the shaft. The bottom end, or end cap of the motor is sealed. I can try slide the top of the spindle up a bit.

The tilt mechanism appears to just be a cam, when the cam unlatches, there's a spring that pushes the whole thing up and level. I stretched out that spring a bit.

I don't have any washers or spacers for the floats, so I'll put it back together as is, and see where I'm at.

[mike_drz]

Re: Pioneer XR-A670 cd changer mechanical issue

No dice, the unit plays fine for a little bit, and then starts rubbing again. I tried pulling the spindle up, but it's friction fit pretty tightly. I used a wooden block with a screw head sticking out of it that goes on top of the spindle. Then I pulled up on the spindle head. It wouldn't budge, even when oiled. I was afraid I'd bend the spindle head.

This thing is all plastic, it doesn't seem to be pioneer's best work. It even uses screws as shafts, if you tighten them too much, things will bind.

[Longbow]

Re: Pioneer XR-A670 cd changer mechanical issue

Replace the rubber mounts as suggested. Spraying them won't do anything.

[R_J]

Re: Pioneer XR-A670 cd changer mechanical issue

If you want to move the spindle up a bit, I use a flat blade screwdriver between the motor and the spindle, twist the screwdriver a bit and the spindle should move up, don't pry it or use too much force, this also works to remove the spindle if the motor needs to be replaced. pulling on the spindle itself can break it or deform it
Or it could be that the plastic on this unit is warped a bit, they are cheaply built