ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi all,
First post here, so hello to you all to start with
I've just got hold of a Beocentre 3500 music centre.
After carefully balancing the arm and checking the stylus, it all seems great.
I have a bit of a problem though - for some reason, after pressing both the "L MONO R" buttons (I'm a born lever puller) to test it, when I released them again to go back to stereo output, it's *generally* ok, but every so often (especially when I've just turned it on), I'll get either the left speaker or the right speaker sounding scratchy. This also happens on headphones
Selecting both speakers to be mono works 95% of the time, but even on that setting it can occasionally be scratchy - but in Stereo it does it completely randomly. Though saying that, it's playing an LP right now with no problems. Seems to be intermittent.
Question - would this likely be resolved by cleaning the switch contacts?
If so, how hard a job is this?
Thanks in advance for any help!
PS - absolutely loving it when it's working though - it's been too long since I heard some decent vinyl!
Cheers
Max
Yes indeed,it's the switch contacts.They become tarnished with age and from the atmosphere.If its come from smokers home,it will be particularly so.
You can spray some contact cleaner/lubricant into the switch assembly,after removing the bottom of the Beocentre.You will see the switch action,and can spray into the contact area using the long thin nozzle supplied with the cleaner aerosol.
This won't provide a permanent cure,as the solvent will eventually dry out,but at least it will allow you use and enjoy the unit.I imagine that the slider controls will also need a squirt,but you will need to remove the top plate/turnatable assembly for access.
Nice unit,enjoy.
Nick
Excellent - thanks very much for the reply and the information.
I've been recommended some DeOxit - or something that sounds similar to that, so I'll give that a go.
There is a tiny bit of scratching while I'm moving the volume control, but it goes when I stop moving it. I'm possibly not confident enough at the moment to take the assembly apart yet, but will definitely try and clean the switches.
Thanks again for your help
I'm not familiar with "deoxit".Is it specifically a switch contact cleaner?You need to use something that won't attack the plastic contact carriers.
If you are in the U.K.you can get appropriate cleaners from Maplin stores,or say R.S.Components.
I've been told that it's good for cleaning contacts, but, as an update, over the last 2 weeks or so, I've noticed that the problem has pretty much gone away. For the first 10-20 seconds straight after turning it on it might do it for a bit, but after that, it's normally fine all the time. So it might be settling in now.
Also, quick daft question, how the hell do you get it to play 12"'s at 45rpm? Even setting the dial to what the manual says to do either makes it think it's a 7" and still plays at 33rpm, or just a full size lp at 33rpm. No matter what setting I put the dial on, it never seems to do 45rpm.
And as an update, it's starting to lose the sound again.
I've noticed that when I fiddle with the L MONO R switches, it can make it come back on, but last night I noticed that If I press pretty much any switch down, and hold it down with a small amount of pressure (which is moving the entire switch assembly down a bit) it always works 100%.
So this indicates to me that perhaps it isn't a single switch problem, but the actual switch housing itself? Would anyone agree?
I'm a bit reluctant to start taking it to bits to closely examine it, as I'm concerned I'll not be able to get it all back together in one piece!
Does anyone know what the procedure is to clean/examine the switch assembly? Is it as simply as unscrewing the fascia at the front and then examining the switches?
Any help would be really appreciated
Thanks
The symptoms, you describe, is typical of oxidized contacts and since the signal path loops through countless contactson the frontpanel, it will only take one bad contact to spoil the fun.
Give the contacts a shot of contact cleaner from behind and exercise them all 20-40 times.Normal use will also restore lots of problems with oxidized contacts. The Mono buttonsare rarely used so they will often have heavy oxidation and will then fail the first times when suddenly used again.
Martin
Hi Martin - thanks for the reply.
I didn't think of the rarely used switches having the most amount of oxidation - doh! Makes complete sense.
Is it fairly straightforward to get at the back of the switches? Just the fascia to be removed?
Thanks,
Remove the bottom plate instead.(Remember to remove the platter, cartridge etc. and support the Beocenter on a foam pillow or similar to avoid damage to the tonearm beforeremoving the bottom plate).The best way is to take it all apart and clean the parts separately, obviously, but it is a job that can take several days and not one I enjoy doing myself.The "bandit" way is to lift up the Beocenter, get a helper to hold it frontpanel down over an old towel or similar (to catch drops and dirt), sprayliberal amounts of contact cleaner into the contacts, almost flooding and flushing them. Put the Beocenter down and exersize the switches.Spray and flush out again.
Try to find a contact cleaner that evaporates fully (or as close as it gets), so it won't just add to the mess in there.
Many thanks for the info.
Hm, the sensible part of me is saying to take it all apart and dedicate a few days to clean it all. Though that's going to be a pain and will take me a lot longer than someone who's used to doing it. It took me a few hours just to balance the tonearm!
Tempted for the bandit method :-)
If I try the bandit method, I don't have to remove anything? Just hold the unit up with the front panel facing down and fire the contact cleaner into the switches?
You will have to remove the Beocenters black metal bottom plate to get to the backside of the switches.You will easily find the small white (or yellow'ish with age) plastic formers that holds the actual (tiny) bronze contacts inside.You can see them move in and out as you operate the switches. They have small opening at the rear that you can spray into.You don't have to take anything apart to this, besides the bottom plate.
Something like this, just the frontpanel downwards.In this photo, you can see one button, the rightmost (Loudness) is depressed and its white plastic former sticking out a bit.
http://archivedarchivedforum2.beoworld.org/cfs-filesystemfile.ashx/__key/CommunityServer.Components.PostAttachments/00.00.35.71.98/BEO_5F00_3000-004_5F00_bottom.JPG
Ahh, I'm with you - I see what you mean now. Thanks very much!
That doesn't seem too bad. It's just making sure the tone-arm and the platter don't get knocked about when I'm moving it.
I'll be doing this on my own you see, so I'm trying to work out in advance the best method of doing it
Well, that unfortunately didn't work as expected.
Got some decent contact cleaner and carefully took the bottom plate off. Rested the unit and cleaned as many of the switches as I could, with them both in the on and off position. There were a couple "up the top end" (i.e., on the left as you look at the unit from the front) that were hard to get to, but I managed to get a bit of spray in there.
Anyway, left it 2 hours to completely dry and tried it.
Worked perfectly with no crackle at all. Even deliberately went through the switches and everything was fine.
For 20 minutes.
Then it just almost cut out completely - it was like I'd turned the volume down to 1. And no matter what I did, or how long I waited, I couldn't get it to work again.
Left it overnight and tried again this morning - exactly the same thing.
So back to the drawing board I think
What kind of cleaner did you use ?
It was the WD-40 specialist contact cleaner - http://www.maplin.co.uk/wd-40-specialist-contact-cleaner-621346?c=maplin&utm_source=gcs&utm_medium=gcs_search&utm_campaign=N94LJ&utm_content=Electronics+Cleaners