B&O Beocenter 2002 treble issue - UK Vintage Radio Repair and Restoration Discussion Forum

martynmcg · 24th Feb 2019, 12:40 pm

Hi
I recently repaired a Beocenter 2002 that had few problems and now takes pride of place in my living room.
After thinking it was working properly I have just realised that the treble adjustment does not work on the right channel; it does on the left.
I have swapped the speaker around and the same channel is the problem so that rules out the speakers themselves.
Does anyone have any ideas what components I should be checking?
I figure the slider itself is ok given that one channel still adjusts?

Many thanks
Martyn

Beobloke · 25th Feb 2019, 2:12 pm

I wouldnt assume this as sometimes the sliders fall apart internally. I have a Yamaha A-960II amplifier with exactly this problem, awaiting my attention!

ekjdm14 · 25th Feb 2019, 4:07 pm

Seconded, I would imagine it's actually more likely to be a problem with the slider than not. I'd expect it to have 2 separate tracks, one to adjust the treble on each channel.

I would give it the Servisol/exercise treatment firstly, and if that failed to bring it back only then would I open the set up to take measurements from the terminals of the pot.

martynmcg · 25th Feb 2019, 8:19 pm

Ahh well if the two channels run through the slider then that’s more likely my problem. By measurements you mean to check for continuity?
Overall it is in very good condition and dosent look to have had too much use so I am hoping the sicker will be fixable!
Thanks for the advice

ekjdm14 · 25th Feb 2019, 11:18 pm

Everything's fixable

I like the quote in someone's signature on here, it goes- "The job couldn't be done... He didn't know that, so he did it".

If it doesn't respond to a drowning in Servisol then yes, I'd measure resistance of both sections of the pot & check that they both change and are somewhat similar.

(By drowning in Servisol I mean, with power disconnected from the unit, jetting enough Super 10 into the slider that it's dripping out, through any openings you can get it to spray through, whilst working the slider back & forth. It's certainly not a cure-all but so far it has a 100% success rate for me.) Obviously then allow sufficient time for solvent evaporation before powering up.

martynmcg · 26th Feb 2019, 9:32 am

Didn’t even know what servisol was; just ordered a can now!
Having fixed all the major problems with it it would be a shame not to get it in fully working condition.
With the expeption of the expensive stylus repair the rest of it has been a cheap fix and fun to do; They are a pretty cheap system by B&O standards but I think it has a great retro look and the sounds is pretty good really (I know audiophiles will disagree!)

ekjdm14 · 26th Feb 2019, 10:34 am

Heck if audiophiles say your Beocenter doesn't sound good they'd have a field day with my Prinz and Sharp music centres! I was shocked at the B&O prices at the local auction recently, over £150 for an Ouverture in unknown condition, £60 for an Avant 32 CRT set etc... It's nice stuff (I keep an 8802 TV) but those prices are crazy!

TonyDuell · 26th Feb 2019, 10:48 am

I have said this many times (and in some cases, not here, been flamed by audiophools) but the real purpose of any radio, record player etc is to produce sounds that YOU enjoy listening to. It doesn't matter why you enjoy it. It may be that your parents had a similar unit and listening to it brings back happy memories of them. It certainly doesn't have to be technically accurate. If you like it then listen to it. If somebody else prefers a different system then that's fine. They listen to that.

My 'take' on B&O is that often you are paying (new and second-hand) for the styling rather than the electronics. It's not badly designed, and it's often well made, but I think there are better units out there. That said, I would like an (old) Beolit to compare to Hacker and Roberts portables. But not at the prices they sell for.

martynmcg · 27th Feb 2019, 6:37 pm

Ok so the servisol didn’t really work however I am now sure the slider is the cause of my problem. After using the servisol the right channel on the trebble became intermittent and the left still none exisitant.
But after some aggressive wiggling I noticed that if I push the slider sideways a bit the trebble adjustment kicks in; however it will not work under normal conditions.
So is there any way to service the slider as I assume a replacement of the exact model I need will be all but impossible to find.
Thanks
Martyn

60 oldjohn · 27th Feb 2019, 6:56 pm

Somewhere on this page https://forum.beoworld.org/search/Se...re&o=Relevance is a detailed repair of the sliders.

Good luck with it, John.

tri-comp · 1st Mar 2019, 6:40 am

There was also a guy (me) on this forum that showed in detail how to repair slider-pot's in a Beomaster-2400.
https://www.vintage-radio.net/forum/...d.php?t=128637
Don't remember if the exact same type was used i a Beocenter-2002, but you should be able to tell.

Rgds,

/Torben

martynmcg · 1st Mar 2019, 10:57 pm

Unfortunately the sliders are different; those look more substantial. After taking it apart to get to them to clean with Servisol the bass slider is now failing too and one of the LEDs has stopped working as well so it wasn’t a very successful attempt at a repair!

ekjdm14 · 2nd Mar 2019, 12:50 pm

Oh dear

that's not a very glowing endorsement of my recommendation! Sorry to hear that it's not helped, is there any chance you could upload some clear photos of the sliders and their internals?

martynmcg · 3rd Mar 2019, 8:31 am

So I managed to fix it; I took it all apart again and managed to get the covers of the slider potentiometers.
It seems that the contact arms and another lever that pre load the contact had just become loose over time so I bent the arms a little further to re engage the contacts and also cleaned a bit of dirt off the tramlines and now they work perfectly.
I did manage to break a solder which rendered the left channel dead so it all had to be taken apart again so I could figure out what I had done!

Thanks again for thoes that helped with this; it was by far the most challenging project I have done getting this thing in full working order but I really enjoyed it. I re wired the tone arm; put new drive belts in the tape deck, re glued the speakers and now finally fixed the sliders. I really love listening to records on this thing and also looking forward to getting another project to work on.
Thanks
Martyn

24th Feb 2019, 12:40 pm	#1
martynmcg Triode Join Date: May 2010 Location: Lancashire, UK. Posts: 23	B&O Beocenter 2002 treble issue Hi I recently repaired a Beocenter 2002 that had few problems and now takes pride of place in my living room. After thinking it was working properly I have just realised that the treble adjustment does not work on the right channel; it does on the left. I have swapped the speaker around and the same channel is the problem so that rules out the speakers themselves. Does anyone have any ideas what components I should be checking? I figure the slider itself is ok given that one channel still adjusts? Many thanks Martyn

25th Feb 2019, 2:12 pm	#2
Beobloke Heptode Join Date: Oct 2007 Location: Southampton, Hampshire, UK. Posts: 821	Re: B&O Beocenter 2002 treble issue I wouldnt assume this as sometimes the sliders fall apart internally. I have a Yamaha A-960II amplifier with exactly this problem, awaiting my attention!

25th Feb 2019, 4:07 pm	#3
ekjdm14 Banned Join Date: Feb 2019 Location: Congleton, Cheshire, UK. Posts: 609	Re: B&O Beocenter 2002 treble issue Seconded, I would imagine it's actually more likely to be a problem with the slider than not. I'd expect it to have 2 separate tracks, one to adjust the treble on each channel. I would give it the Servisol/exercise treatment firstly, and if that failed to bring it back only then would I open the set up to take measurements from the terminals of the pot.

25th Feb 2019, 8:19 pm	#4
martynmcg Triode Join Date: May 2010 Location: Lancashire, UK. Posts: 23	Re: B&O Beocenter 2002 treble issue Ahh well if the two channels run through the slider then that’s more likely my problem. By measurements you mean to check for continuity? Overall it is in very good condition and dosent look to have had too much use so I am hoping the sicker will be fixable! Thanks for the advice

25th Feb 2019, 11:18 pm	#5
ekjdm14 Banned Join Date: Feb 2019 Location: Congleton, Cheshire, UK. Posts: 609	Re: B&O Beocenter 2002 treble issue Everything's fixable I like the quote in someone's signature on here, it goes- "The job couldn't be done... He didn't know that, so he did it". If it doesn't respond to a drowning in Servisol then yes, I'd measure resistance of both sections of the pot & check that they both change and are somewhat similar. (By drowning in Servisol I mean, with power disconnected from the unit, jetting enough Super 10 into the slider that it's dripping out, through any openings you can get it to spray through, whilst working the slider back & forth. It's certainly not a cure-all but so far it has a 100% success rate for me.) Obviously then allow sufficient time for solvent evaporation before powering up. Last edited by ekjdm14; 25th Feb 2019 at 11:23 pm.

26th Feb 2019, 9:32 am	#6
martynmcg Triode Join Date: May 2010 Location: Lancashire, UK. Posts: 23	Re: B&O Beocenter 2002 treble issue Didn’t even know what servisol was; just ordered a can now! Having fixed all the major problems with it it would be a shame not to get it in fully working condition. With the expeption of the expensive stylus repair the rest of it has been a cheap fix and fun to do; They are a pretty cheap system by B&O standards but I think it has a great retro look and the sounds is pretty good really (I know audiophiles will disagree!)

26th Feb 2019, 10:34 am	#7
ekjdm14 Banned Join Date: Feb 2019 Location: Congleton, Cheshire, UK. Posts: 609	Re: B&O Beocenter 2002 treble issue Heck if audiophiles say your Beocenter doesn't sound good they'd have a field day with my Prinz and Sharp music centres! I was shocked at the B&O prices at the local auction recently, over £150 for an Ouverture in unknown condition, £60 for an Avant 32 CRT set etc... It's nice stuff (I keep an 8802 TV) but those prices are crazy!

26th Feb 2019, 10:48 am	#8
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: B&O Beocenter 2002 treble issue I have said this many times (and in some cases, not here, been flamed by audiophools) but the real purpose of any radio, record player etc is to produce sounds that YOU enjoy listening to. It doesn't matter why you enjoy it. It may be that your parents had a similar unit and listening to it brings back happy memories of them. It certainly doesn't have to be technically accurate. If you like it then listen to it. If somebody else prefers a different system then that's fine. They listen to that. My 'take' on B&O is that often you are paying (new and second-hand) for the styling rather than the electronics. It's not badly designed, and it's often well made, but I think there are better units out there. That said, I would like an (old) Beolit to compare to Hacker and Roberts portables. But not at the prices they sell for.

27th Feb 2019, 6:37 pm	#9
martynmcg Triode Join Date: May 2010 Location: Lancashire, UK. Posts: 23	Re: B&O Beocenter 2002 treble issue Ok so the servisol didn’t really work however I am now sure the slider is the cause of my problem. After using the servisol the right channel on the trebble became intermittent and the left still none exisitant. But after some aggressive wiggling I noticed that if I push the slider sideways a bit the trebble adjustment kicks in; however it will not work under normal conditions. So is there any way to service the slider as I assume a replacement of the exact model I need will be all but impossible to find. Thanks Martyn

27th Feb 2019, 6:56 pm	#10
60 oldjohn Dekatron Join Date: Dec 2004 Location: East Yorkshire, UK. Posts: 3,987	Re: B&O Beocenter 2002 treble issue Somewhere on this page https://forum.beoworld.org/search/Se...re&o=Relevance is a detailed repair of the sliders. Good luck with it, John.

1st Mar 2019, 6:40 am	#11
tri-comp Heptode Join Date: Oct 2008 Location: Aalborg, Denmark Posts: 903	Re: B&O Beocenter 2002 treble issue There was also a guy (me) on this forum that showed in detail how to repair slider-pot's in a Beomaster-2400. https://www.vintage-radio.net/forum/...d.php?t=128637 Don't remember if the exact same type was used i a Beocenter-2002, but you should be able to tell. Rgds, /Torben

1st Mar 2019, 10:57 pm	#12
martynmcg Triode Join Date: May 2010 Location: Lancashire, UK. Posts: 23	Re: B&O Beocenter 2002 treble issue Unfortunately the sliders are different; those look more substantial. After taking it apart to get to them to clean with Servisol the bass slider is now failing too and one of the LEDs has stopped working as well so it wasn’t a very successful attempt at a repair!

2nd Mar 2019, 12:50 pm	#13
ekjdm14 Banned Join Date: Feb 2019 Location: Congleton, Cheshire, UK. Posts: 609	Re: B&O Beocenter 2002 treble issue Oh dear that's not a very glowing endorsement of my recommendation! Sorry to hear that it's not helped, is there any chance you could upload some clear photos of the sliders and their internals?

3rd Mar 2019, 8:31 am	#14
martynmcg Triode Join Date: May 2010 Location: Lancashire, UK. Posts: 23	Re: B&O Beocenter 2002 treble issue So I managed to fix it; I took it all apart again and managed to get the covers of the slider potentiometers. It seems that the contact arms and another lever that pre load the contact had just become loose over time so I bent the arms a little further to re engage the contacts and also cleaned a bit of dirt off the tramlines and now they work perfectly. I did manage to break a solder which rendered the left channel dead so it all had to be taken apart again so I could figure out what I had done! Thanks again for thoes that helped with this; it was by far the most challenging project I have done getting this thing in full working order but I really enjoyed it. I re wired the tone arm; put new drive belts in the tape deck, re glued the speakers and now finally fixed the sliders. I really love listening to records on this thing and also looking forward to getting another project to work on. Thanks Martyn Attached Thumbnails