Boegram CD50 carrige slow

[Madskp]

Helle all

I am working on a Beogram CD50 where I have issues with the CD carrige movement. It is very slow, and when it reach the point where it has to lift the CD clamper it stops.

I have replaced the Belt, and cleaned and re lubricated all the gears for the CD carrige movement, and this has helped to some degree.

Also I can move it correctly by hand , so pretty sure I ahve alligened the gears correctly. This also verifies when I try to apply 5V to the CD carrige motor from an external power supply which makes it run smoother and also it is able to lift the CD clamper with this voltage.

So now I am A little in doubt what is wrong:

• Is the motor voltage correct, I Measure 4V/-4V when it is moving, but in the service manual it says 5v/-5V before the transistors around the motor, and as mentioned it runs smoother with 5V applied to it?
• Could the motor also be prone to old lubricant that needs to be cleaned? If so what is the procedure for that, and do I need to dissasemble the whole rail system for the CD carrige to take of the motor?

Thanks in advance

Location: Denmark

[Madskp]

Just to illustrate the issue I have made a small videoclip which shows where it stops in the end of the video

https://youtube.com/shorts/GoGJ3qFGhXY

 

Location: Denmark

[Rob Bune]

In the video the raiser appears to lift at the end of the movement, that looks correct to me.

[Madskp]

Rob Bune wrote:

In the video the raiser appears to lift at the end of the movement, that looks correct to me.

At the time I posted the video I belive that it would raise fully up, and the cam wheel would have to move even further. However I found in an old thread that it is only moving fully up when a disc is detected.

However Where I was at this point I had to adjust the cam wheel one tooth and also adjust the brass nut on the cam wheel further down to make the raiser lift the CD high enough to reach the spindle that drives the disc.

The Brass nut had some sort of locking glue on top (the green stuff on the pictue) That indicates where it was placed originally, but it can be hard to see if it should have one revolution more even with a before picture.

Location: Denmark

[Madskp]

And now after disassembeling and reassembeling things one more time I got it playing again https://youtu.be/1yETrPtyj18

Now I will wait and see for how long it does that. So it might be up to small things. One thing I have noticed is that the brass nut is sometimes moving a little in position. I have now tried to secure it with some super glue at the top to see if that also helps for stability

Location: Denmark

[Madskp]

Had some issues with CD’s not playing or starting 1-2 minutes into track 1.

Reading in this older thread https://archivedforum2.beoworld.org/forums/t/628.aspx?PageIndex=1

It is mentioned that this could be due to the spindle motor not being able to get up to high enough rpm to read the start of the first track which is placed in the inner part of a CD.

It seems like a few people in that thread had luck disassembeling the spindlemotor cleaning and relubricating it.

After trying a few other things I decided to do the same. It was actually easier for me than I thought it would be based on the description in that old thread.

I guess it is down to applying enough force on the motor PCB and pressing the shaft against som metal.

Be aware as mentioned in that old thread that the brass ring that comes of has a chamfered edge that has to point against the motor

The spacers mentioned in the other thread did not fall of on mine so I let them be where the were and concentrated on cleaning and relubricating the shaft and bearing

Pressing the brass ring on the shaft again was actually harder for me than getting it of. It is easily pressed to much against the bearing making the motor hard to spin. I found that placing a guitar plector between the motor housing bell and the PCB when pressing the brass ring on gave just the right amount of clearance.

Aftewards it was just placing the CD spindle in the same distance as before disassembely and the reassemble the CD mechanism.

All in all I used maybe half an hour on this.

The result: Every CD I have tried no starts at 0.00 on track 1. Of course I have to long term test it, but I allready think this was worth it 😀

Next up the non responsive Beocord 5000 to keep the CD50 company

• This reply was modified 1 week, 3 days ago by Madskp.

Location: Denmark

[Madskp]

And just to round this up I have also replaced the three capacitors mentioned in Beolovers blogpost https://beolover.blogspot.com/2021/06/beogram-cd50-typical-restoration-steps.html?m=1 which has also been a great reference in regards to replacing the belt.

Last thing to check is the datalin control which I tested by connecting it to my Ouverture

And it is working just great with full control 😀

Location: Denmark

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