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[CLD-95] B side play problems
https://forum.lddb.com/viewtopic.php?f=53&t=9423		 Page 1 of 2
Author:  staffanu [ 17 Oct 2020, 13:14 ]
Post subject:  [CLD-95] B side play problems
Hi,

I fixed a broken gear + dc motor in a CLD-95 recently, and now the player works again. It looks as if alignment in general is quite good since search times are normal and the picture seems fine. However, most of the times it won't play the b side of discs. There is no apparent pattern regarding what discs work and not.

The player spins up on the b side and I can hear (and see) the pickup moving up and down. So, I"m assuming a lack of focus. When fixing the optical assembly, I took the whole mechanism assembly out and also removed the top plate, so I'm thinking b side centering might be off. However, would that really affect focusing? Since I'm not sure I thought I have nothing to lose by trying to adjust it.

So, two questions: 1) is there anything else that is an obvious first thing to check? 2) I really cannot understand how to use the eccentric screwdriver to adjust this thing. The picture in the manual and one from reality are attached.

I guess the point is to move the whole thing horizontally, so I could probably figure out a way to do it, but I thought I'd ask before removing the seal that keeps it in its current place. Also, I do not actually have the GGV-129 eccentric screwdriver but found a picture here in the forum and ground down a screwdriver to something that I think would work if I only knew how:)

Any other pointers appreciated!

Staffan

Attachments:
Service manual adjustment position.png
Service manual adjustment position.png [ 465.17 KiB | Viewed 3229 times ]
b-side centering adjustment-small.jpg
b-side centering adjustment-small.jpg [ 475.2 KiB | Viewed 3229 times ]
Author:  krbahr [ 18 Oct 2020, 01:24 ]
Post subject:  Re: CLD-95 b side play problems
Yes, just move the upper part to the left and right to find the two extremes where the picture starts breaking and set it between the two extremes.
Author:  staffanu [ 19 Oct 2020, 14:43 ]
Post subject:  Re: [CLD-95] B side play problems
Thanks will try that. But how to use the special tool is still a mystery to me.

Staffan
Author:  rein-o [ 19 Oct 2020, 16:01 ]
Post subject:  Re: [CLD-95] B side play problems
I've never seen it or possibly Grasshopper sent a pic once.
I think its the type of thing that is round with a pin on the other end but its not in the center, so when you turn
it would rotate but pin is off center.

Hope that makes sense.
Author:  cplusplus [ 19 Oct 2020, 20:34 ]
Post subject:  Re: [CLD-95] B side play problems
rein-o wrote:
I think its the type of thing that is round with a pin on the other end but its not in the center, so when you turn
it would rotate but pin is off center.


Yep. Instrumental Parts will sell you one for $267.00 + shipping. :crazy:
Author:  rein-o [ 19 Oct 2020, 21:32 ]
Post subject:  Re: [CLD-95] B side play problems
WOW that's a lot of dough.

I really wish I could remember what I used when I adjusted my 3070, could have been needle nose pliers????
I feel it was a regular screwdriver but can't remember.
Author:  staffanu [ 19 Oct 2020, 21:38 ]
Post subject:  Re: [CLD-95] B side play problems
There is a picture in this thread: https://forum.lddb.com/viewtopic.php?f=30&t=2521

So yes, I know what it looks like, but I fail to see how it would be useful for the adjustment in question. I'm assuming there is an aha moment when someone explains it to me:) But the mechanism doesn't seem that complicated so I'll just move the thing... In the middle of another project right now but in a few days I'll report how it went.

Staffan
Author:  krbahr [ 20 Oct 2020, 00:00 ]
Post subject:  Re: [CLD-95] B side play problems
If you look at the picture you’ll see two bumps, one on each side used for adjustment limits. Take a flat blade screwdriver, put it between the adjustment piece and the bump, turn the screwdriver to move the adjustment piece over one direction. You use the other bump with the screwdriver on the other side to move it the other way. I’ve used other methods but this seems the best. I’ve tried using a grinder to bring a screwdriver to have a point to put in the hole and move the adjustment piece but the screwdriver against the bump works just fine.
Author:  cplusplus [ 20 Oct 2020, 00:40 ]
Post subject:  Re: [CLD-95] B side play problems
Kurtis, can something similar be done for the side A tangential adjustment that also calls for GGV-129?
Author:  krbahr [ 21 Oct 2020, 00:47 ]
Post subject:  Re: [CLD-95] B side play problems
cplusplus wrote:
Kurtis, can something similar be done for the side A tangential adjustment that also calls for GGV-129?


I use my modified screwdriver for that one.
Author:  staffanu [ 21 Oct 2020, 15:12 ]
Post subject:  Re: [CLD-95] B side play problems
Hi again,

This is annoying, but now that I thought I'd make the adjustment the player doesn't want to spin up on the b side. I've seen it before but only once or twice and lately when I've checked the disc has spun up. I wonder if this points so something else being at fault (centering could still be off but that's hard to adjust right now). Any ideas?

Staffan
Author:  cplusplus [ 21 Oct 2020, 15:30 ]
Post subject:  Re: [CLD-95] B side play problems
krbahr wrote:
cplusplus wrote:
Kurtis, can something similar be done for the side A tangential adjustment that also calls for GGV-129?


I use my modified screwdriver for that one.

Thanks Kurtis. Time to find someone that can make this for me.

staffanu- If you don't have an oscilliscope, centering is going to be a tedious trial and error situation of very, very small adjustments to hit the sweet spot.
Does the pickup still try to focus on Side B?
Author:  staffanu [ 21 Oct 2020, 15:53 ]
Post subject:  Re: [CLD-95] B side play problems
I do have an oscilloscope. But as I said, right now the disc won't spin up at all. The player has been in this state before but then it started to always spin up but again giving up shortly after.

So, right now if I have a disc in the tray and press the B button, the optical assembly goes all the way upp to b side playing position, and I can also see and hear it raise the pickup. But then it is apparently unhappy and doesn't start spinning the disc. Does it focus before spinning of the disc or after?

Anyway, I assume centering cannot be important for my current problem.

Staffan
Author:  krbahr [ 21 Oct 2020, 23:41 ]
Post subject:  Re: [CLD-95] B side play problems
In test mode it should spin the disc after you press the play button. It only needs to detect a disc is there to spin , it does not have to read the data to keep spinning in test mode.
Author:  cplusplus [ 22 Oct 2020, 01:16 ]
Post subject:  Re: [CLD-95] B side play problems
staffanu wrote:
Does it focus before spinning of the disc or after?

The focus is "locked" then the spindle starts.
Author:  staffanu [ 22 Oct 2020, 04:38 ]
Post subject:  Re: [CLD-95] B side play problems
I was experimenting with this a bit now. If I start the player in test mode and press the B button to start side B play directly, the tray loads the disc, and looking at the IMODE / SMODE numbers, it gets to IMODE 0 after the tray is closed.

I sometimes see it pass SMODE 3, always SMODE 4, and most of the time (maybe always -- I think it gave up at SMODE 4 once but I'm not sure) it moves to SMODE 8 for a second or so before returning the slider to side A and stops.

So, test mode but disc is not spinning. This is regardless of playing an 8" or 12" disc (which is strange since the manual indicates that it should move to SMODE 9 for non-8" discs).

The height switch changes its state a few times and I can also hear and see the pickup moving up and down. (Since this is what I fixed I'm keeping an extra eye on it...)
Author:  krbahr [ 23 Oct 2020, 01:45 ]
Post subject:  Re: [CLD-95] B side play problems
Does it spin for side A?

After it loads in test mode you have to hit “play” to get it to spin and then hit it again to engage the tracking servo.
Author:  staffanu [ 23 Oct 2020, 13:49 ]
Post subject:  Re: [CLD-95] B side play problems
Yes side A spins in test mode.

Normal play for the A side works well. Skipping, searching, etc works perfectly (I don't know if it can be faster but it seems normal) and the picture is good.

BTW, on the B side, after "raising" the optical assembly (it's actually going downwards, since the whole assembly thing is upside down at that point) to get closer to the disc surface, I can also see the lens moving out towards the disc in a motion that takes maybe half a second. It is just when it looks as if it hits the disc (or is very close) that it gives up.

If I have no other ides I'll have a look at the focus signal while this happens (and compare with the A side). I'm not sure this will be easy, though since the time of interest is probably very short so triggering might be problematic. Maybe I can capture data at a relatively high frequency during a few seconds.
Author:  staffanu [ 24 Oct 2020, 21:21 ]
Post subject:  Re: [CLD-95] B side play problems
Hi again,

Not much new information: I looked at the focus A+B signal when starting playback on side A a couple of times, and as expected it goes high (9-10 V) with some noise just after raising the pickup. On side B, nothing happens, i.e., not even noise. Solid 0V.

One time, out of maybe 20 attempts to start side B play, it did something different: the lens was moving up and down maybe 5 times until it gave up. Didn't measure that time, though.

Is it possible, or rather, it is likely, that something is broken in the pickup that makes it not work when upside down? I tried tilting the machine almost 90 degrees when B side play is about to start but no difference. (A somewhat dangerous maneuver since the disc wants to fall out when it gives up and doesn't clamp it anymore.) I would think that if say, some connection is slightly loose, playback would sometimes fail on the A side too...

Staffan
Author:  krbahr [ 25 Oct 2020, 04:38 ]
Post subject:  Re: [CLD-95] B side play problems
It could always be the cable between the preamp board in the mechanical assembly and the mainboard.
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