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Beocenter 9500 tape deck squeaking noise and transformer humming noise

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Motorman
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Motorman posted on Wed, Jan 13 2021 8:50 PM

Dear all,

I'm new to the forum but I've already learned a lot here and have to thank you for that!

I have two Beocenters 9500.

I own the first one since round about 2000 when I bought it used. It allways worked very wel,l aside from the tape deck which i rarly use, since last December. Then the CD Player stoped working. I found  a speciallist and he took care of the issues. He told me that he replaced the belts of the tape deck (3 Belt version) and exchanged the CD Player.  When I got it back I started hearing my old taps (Maxells from the 80's), which to my amazement did sound very good. Unfortunately after some taps the deck startet to produce a very loud squeaking noise, it was almost like an alarm!

Could anybody in the forum give me a hint where the noise is coming from and how I can fix it?
I do not want to get it back to the repair shop, because this is quite a drive.

Now to my second Beocenter. I just bought it end of last year. The CD player did not work, the CD door got stuck, the lower glas panel was loose, and only one speaker at the speakers 1 outputs was working. But to my amazment the tape deck worked fine. I got it for 50 € with the thought to use it as a spare parts donor.

Then I discovered this amazing forum. With the Informations I found here I fixed most of the issues the Beocenter had:

  • The CD player had the capacitor issue which I fixed with new parts from Dillen
  • The CD door is now working nice after I executed an instruction I found here in the forum.
  • I glued the panel back with Loctide 480 which a menber recommended and this worked perfect.
  • The reason why one chanel was not working was the mute relay (as usal as I learned here)
So this Beocenter is now working almost perfect again. From a functional side there is only one issue left.
The transformer is producing a low but annoying humming noise which my old Beocenter does not do.
Does anybody here in the forum know a cure for this? I have unfortunately not found a helpfull thread regarding this issue.
The other issue I have is only from astetic nature. There are some slight scratches in the pollished alluminium parts. Is it some how possible to polish these up or to replace them without spending a fortune?

By the way this Beocenter has a different tape deck with only one belt. Are both deck inter change able?
I'm just curious. My goal is to get both back to perfect working conditions and to maybe sell one on later. If I can bring my self to do it!

Kind regards,
Wolfgang

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Dillen
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Answered (Verified) Dillen replied on Thu, Jan 14 2021 11:07 AM
Verified by Motorman

Wrong belts perhaps?...  https://forum.beoworld.org/forums/p/38090/289608.aspx

If the motor starts to whine after running a few hours or days (or even immediately), the drive will most likely have run with to tight belts.

You can try to lubricate the motor bearings - if not already to late, and make sure the belts are correct (beoparts-shop).
If bought off Ebay throw them away before they damage anything or more. 

The two drive types are NOT interchangeable. The tape controller board, the connection boards behind the drive, the wire loom etc. must be replaced as well.
I don't remember if the processor module differs too.

Martin

Dillen
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Answered (Verified) Dillen replied on Thu, Jan 14 2021 11:47 AM
Verified by Spassmaker

Guy:

But if you buy the belts from Martin (Dillen) they come with excellent fitting instructions.

If you order from Beoparts-shop just put a note in with your order, stating your model (Beocenter 9500), instructions will then be included - if available.
Indeed, for Beocenter 9500 instructions are available.

Martin

Motorman
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Verified by Motorman

 

Dear all,

today, one more with the help of Dillen (Martin) I fixed the humming noise issue.

He provided me with rubber bushing, which he has in stock for the transformers of several Beomasters.

https://www.beoparts-shop.com/product/transformer-bushings-beomaster-3500-4500-5000-5500-6000-6500-7000-etc/

They perfectly fit in the Beocenter 9500 as well!

The Black bushings are the new ones. Some of the old ones simply crumbled during dismantling!

The new ons fit perfect on top and below the transformer and dampen the humming noise considerably. Its almost not audible any more and no longer bothers at all. Befor the repair it did sound like an angry wasp in the room.

I'm happy now and I hope this wil help others with similar issues.

Kind regards,

Wolfgang

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Motorman
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Motorman replied on Thu, Jan 14 2021 10:27 AM

I have on further question:

The Service manual of  the Beocenter 9500 shows only the "One" Belt tape deck version.

Where can I find an exlosion drawing for the 3 Belt tape deck version?

Dillen
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Answered (Verified) Dillen replied on Thu, Jan 14 2021 11:07 AM
Verified by Motorman

Wrong belts perhaps?...  https://forum.beoworld.org/forums/p/38090/289608.aspx

If the motor starts to whine after running a few hours or days (or even immediately), the drive will most likely have run with to tight belts.

You can try to lubricate the motor bearings - if not already to late, and make sure the belts are correct (beoparts-shop).
If bought off Ebay throw them away before they damage anything or more. 

The two drive types are NOT interchangeable. The tape controller board, the connection boards behind the drive, the wire loom etc. must be replaced as well.
I don't remember if the processor module differs too.

Martin

Guy
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Guy replied on Thu, Jan 14 2021 11:34 AM

Motorman:
Where can I find an exlosion drawing for the 3 Belt tape deck version?

If it helps, the 3-belt deck is very similar to the one in the BS2500, here: https://www.youtube.com/watch?v=JnAD5PbyBGA

But if you buy the belts from Martin (Dillen) they come with excellent fitting instructions.

Dillen
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Answered (Verified) Dillen replied on Thu, Jan 14 2021 11:47 AM
Verified by Spassmaker

Guy:

But if you buy the belts from Martin (Dillen) they come with excellent fitting instructions.

If you order from Beoparts-shop just put a note in with your order, stating your model (Beocenter 9500), instructions will then be included - if available.
Indeed, for Beocenter 9500 instructions are available.

Martin

Motorman
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Motorman replied on Thu, Jan 14 2021 11:49 AM

Hi Martin,

thanks for the quick reply! As I wrote above the belts have been change at a professional B&O Service workshop. I therefore assumed that the correct belts were used. But it seems that I have no luck with repair shops. Its the same with cars. If I want to have it done properly I have to do it my self.

I will order the right belts from your shop and hope that no permanent damge is done to the motor or other bearings!

What kind of grease or do you propse for lubricating the motor bearings?

Hi Guy,

thanks for the vieo link. That is very intersting!

 

Kind regards,
Wolfgang

Dillen
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Dillen replied on Thu, Jan 14 2021 11:59 AM

Motorman:

As I wrote above the belts have been change at a professional B&O Service workshop.

B&O has been unable to supply belts for these decks for decades.
You could ask them, where they got the belts from.
And, if it was done recently, bring the Beocenter in under warranty.

Martin

Motorman
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Motorman replied on Thu, Jan 14 2021 12:21 PM

You are right, that would normaly be the right way to proceed.

But the work on the other Beocenter has me hooked and I want to try it out for myself. Then I will really know what has been done.
This will also save me some driving and nerves.

By the way do you have an idea regarding the humming noise of the second Beocenter?

Wolfgang

Dillen
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Dillen replied on Thu, Jan 14 2021 12:29 PM

Motorman:

an idea regarding the humming noise of the second Beocenter?

Could be an overload issue or the mains transformer itself.

Martin

Motorman
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What lubricant should I use for the motor bearings?

I don't want to make things worse.

How can I determine if the motor bearing worn out? How much play is allowed?

Kind regards,

Wolfgang

Dillen
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Dillen replied on Thu, Jan 14 2021 5:23 PM

Use only an oil meant for sintered bronze bearings.
Never WD40, everyman oil, handy oil, 3-in-1 or similar junk.

Originally SAE30 was used, but I'm not sure if it still has the right additives from all manufacturers, so I am a little reluctant about recommending it.
I use Mobil Velocite 6 ("high speed spindle oil").

There should be no sideways play.

Martin

Motorman
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Thanks for the advice. I ordered some of th Mobil velocite 6 oil.

I learned that I can use it for the sewing machine of my wife too.

I'm looking foreword of fixing the tape when I get the belts. I will report how it works out.

Kind regards,

Wolfgang

 

 

 

 

 

Motorman
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Dear all,

2 days ago I found time to fix the squeaking noise.

I got the Belts from Dillen with a perfect fitting instruction and some Mobile Velocite 6 oil as he recommended.

Opening up the BC I found that the "Specialist" has fitted a simple O-Ring with a round cross section, as you can see on the next picture.
That totally different to the belt Dillen send me!

So I replaced this on and added some stingy drops of oil to the bearing indicated with the red arrow

Due to the fact that I got a complete set of belts I exchanged the others too. As Dillen wrote in his instruction it is much easier than it looks.
Only to fiddle the flat belt around the components on the PCP, which you cant see, is a bit of a challange.

At last I had to fix a common issue with these typs of tape deck. The plastic frame was broken. Luckily not completely.
I could glue it with some Industrial super Glue and added some fillement to strengthen the area.

Now I could reassemble everything and the tape deck is now playing like a dream!

Motorman
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Germany (close to Rhine)
29 Posts
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Verified by Motorman

 

Dear all,

today, one more with the help of Dillen (Martin) I fixed the humming noise issue.

He provided me with rubber bushing, which he has in stock for the transformers of several Beomasters.

https://www.beoparts-shop.com/product/transformer-bushings-beomaster-3500-4500-5000-5500-6000-6500-7000-etc/

They perfectly fit in the Beocenter 9500 as well!

The Black bushings are the new ones. Some of the old ones simply crumbled during dismantling!

The new ons fit perfect on top and below the transformer and dampen the humming noise considerably. Its almost not audible any more and no longer bothers at all. Befor the repair it did sound like an angry wasp in the room.

I'm happy now and I hope this wil help others with similar issues.

Kind regards,

Wolfgang

Martin
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Martin replied on Sat, Jan 30 2021 8:39 PM

Thank you for the detailed descriptions! I have recently gone through the exact same thing on my Beocord 4500 deck which uses the exact same mechanism.

I was also terrified by the loud screeching which only stopped when the system was powered down.

I too replaced all belts and it was finally the lubrication of the motor itself with SAE30 oil (thanks Dillen) that seems to have fixed that problem for now! Hopefully it lasts.

I even had the same crack in the plastic cover, so it was as if all pictures could have been taken by myself. :-D

And finally, I have noticed the humming of the power supply on my Beomaster 4500 so thanks a lot for the tip on the new rubber bushings. I did not know they could be found on beoparts. I will fix that one soon too!

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