B&O Beocenter 4600 Tape Deck Faulty Channel - UK Vintage Radio Repair and Restoration Discussion Forum

Zelandeth · 23rd May 2016, 10:59 pm

Mods - wasn't sure if this should be in here or hi-fi but the fault is entirely tape related I figured here was appropriate, apologies if I guessed wrong.

You can imagine the expression on my face a couple of days back when I was at the tip disposing of some of the junk from my late father's house when in the electronic waste bin I spotted a gleaming brushed aluminium slab. Initially I thought from the profile that it was a Philips V2000 VCR, which would have been enough of a shock - but I abruptly realised that it was even worse a thing to see in the tip - an almost immaculate B&O Beocenter 4600.

Almost gave me a hernia lifting it, but it was in the back of the car and I was gone before anyone could blink. Throwing something like that in the tip...it's like trading a Rolls-Royce in for a Ford Fiesta...it's just wrong. Anyhow, it's in safer hands now and has a far brighter future ahead than it looked like 48 hours ago.

After refitting a plug (the original was yanked off when I liberated it as that was buried deep in the pile of junk), everything works, even devoid of scratchy sliders or intermittent push buttons.

The only fault is with the tape deck. The right channel works and is as clear as a bell, the left though is almost dead - there's a pop when you turn the deck on (it has its own power switch), and a faint click when you press play - if you crank the volume up you can distantly hear music too. Interestingly, turning the Dolby NR on and off again results in a very brief burst of audio from the channel too.

I have exercised all of the relevant buttons in case they were to blame without any effect.

Haven't has the cover off yet, but can anyone suggest any likely candidates? Given it was at the tip I've no idea if it's taken a whack (though the lack of scuff marks or damage to the turntable cover suggest otherwise), could be as simple as a wire having come adrift somewhere or a dry joint I guess...

Will put up a couple of photos when I'm at an actual computer tomorrow.

SeanStevens · 24th May 2016, 8:09 am

What a lucky escape for such a nice piece of kit!

I have benefited from a donation of B&O stuff in the past and have been hooked ever since.

I may not be able to help you with the cassette player, other than get you to confirm that both channels work for everything else? Also you could try recording something from record or radio and see if it reproduces on both channels….. if not, see if the recorded stuff you just made is stereo on another machine (this would indicate that the recording was ok on the machine if nothing else)

SEAN

60 oldjohn · 24th May 2016, 9:12 am

I had one corroded wire on the switch bank resulting in dead channel on record player. All the other wires were OK. I expect you have checked the flexible wire from tape head and cleaned the heads. On mine every switch was very stiff or seized. I had to remove the buttons and clean the grease of every finger and replaced it with a silicone grease. I hope the MMC20S is OK. If the tape head has gone on yours forum member Chris Wood 1900 should be able to help you with parts.

Good luck with it, John.

60 oldjohn · 24th May 2016, 9:45 am

I would expect on some preset resistors to need changing on B&O kit of this age. Mainly the idle current for each channel and possibly low volts preset. These as you may know are a change on site parts.

John.

Zelandeth · 24th May 2016, 6:43 pm

Haven't had a chance to do any physical checks yet as I have guests staying at the moment. Will be a week or so probably before I can devote any real time to it.

Stereo output is fine from everything else, it's just the tape that isn't perfect. There's something there, just very muted. The tapes I've been using are pre-recorded and play fine in other machines. Haven't tried recording with it yet.

Was thinking probably a broken wire to the head or switch that was to blame. I've zero experience with these machines, so feel free to point out any usual suspects.

julie_m · 24th May 2016, 8:31 pm

Not specific to this model, but the play/record switch in every 2-head tape deck does some pretty drastic rewiring of the internal circuitry, and just one poor contact here can cause all manner of symptoms. It's well worth a good squirt of Servisol and some vigorous exercise.

23rd May 2016, 10:59 pm	#1
Zelandeth Heptode Join Date: Jun 2006 Location: Milton Keynes, Buckinghamshire, UK. Posts: 931	B&O Beocenter 4600 Tape Deck Faulty Channel Mods - wasn't sure if this should be in here or hi-fi but the fault is entirely tape related I figured here was appropriate, apologies if I guessed wrong. You can imagine the expression on my face a couple of days back when I was at the tip disposing of some of the junk from my late father's house when in the electronic waste bin I spotted a gleaming brushed aluminium slab. Initially I thought from the profile that it was a Philips V2000 VCR, which would have been enough of a shock - but I abruptly realised that it was even worse a thing to see in the tip - an almost immaculate B&O Beocenter 4600. Almost gave me a hernia lifting it, but it was in the back of the car and I was gone before anyone could blink. Throwing something like that in the tip...it's like trading a Rolls-Royce in for a Ford Fiesta...it's just wrong. Anyhow, it's in safer hands now and has a far brighter future ahead than it looked like 48 hours ago. After refitting a plug (the original was yanked off when I liberated it as that was buried deep in the pile of junk), everything works, even devoid of scratchy sliders or intermittent push buttons. The only fault is with the tape deck. The right channel works and is as clear as a bell, the left though is almost dead - there's a pop when you turn the deck on (it has its own power switch), and a faint click when you press play - if you crank the volume up you can distantly hear music too. Interestingly, turning the Dolby NR on and off again results in a very brief burst of audio from the channel too. I have exercised all of the relevant buttons in case they were to blame without any effect. Haven't has the cover off yet, but can anyone suggest any likely candidates? Given it was at the tip I've no idea if it's taken a whack (though the lack of scuff marks or damage to the turntable cover suggest otherwise), could be as simple as a wire having come adrift somewhere or a dry joint I guess... Will put up a couple of photos when I'm at an actual computer tomorrow. __________________ Zel's Lair - A random bag of vintage tech, lighting information and other assorted geekery

24th May 2016, 8:09 am	#2
SeanStevens Octode Join Date: Sep 2009 Location: Bath, Somerset, UK. Posts: 1,033	Re: B&O Beocenter 4600 Tape Deck Faulty Channel What a lucky escape for such a nice piece of kit! I have benefited from a donation of B&O stuff in the past and have been hooked ever since. I may not be able to help you with the cassette player, other than get you to confirm that both channels work for everything else? Also you could try recording something from record or radio and see if it reproduces on both channels….. if not, see if the recorded stuff you just made is stereo on another machine (this would indicate that the recording was ok on the machine if nothing else) SEAN __________________ There are only 10 types of people, those who understand the binary system, and those who don't.

24th May 2016, 9:12 am	#3
60 oldjohn Dekatron Join Date: Dec 2004 Location: East Yorkshire, UK. Posts: 3,987	Re: B&O Beocenter 4600 Tape Deck Faulty Channel I had one corroded wire on the switch bank resulting in dead channel on record player. All the other wires were OK. I expect you have checked the flexible wire from tape head and cleaned the heads. On mine every switch was very stiff or seized. I had to remove the buttons and clean the grease of every finger and replaced it with a silicone grease. I hope the MMC20S is OK. If the tape head has gone on yours forum member Chris Wood 1900 should be able to help you with parts. Good luck with it, John.

24th May 2016, 9:45 am	#4
60 oldjohn Dekatron Join Date: Dec 2004 Location: East Yorkshire, UK. Posts: 3,987	Re: B&O Beocenter 4600 Tape Deck Faulty Channel I would expect on some preset resistors to need changing on B&O kit of this age. Mainly the idle current for each channel and possibly low volts preset. These as you may know are a change on site parts. John. Last edited by 60 oldjohn; 24th May 2016 at 9:56 am.

24th May 2016, 6:43 pm	#5
Zelandeth Heptode Join Date: Jun 2006 Location: Milton Keynes, Buckinghamshire, UK. Posts: 931	Re: B&O Beocenter 4600 Tape Deck Faulty Channel Haven't had a chance to do any physical checks yet as I have guests staying at the moment. Will be a week or so probably before I can devote any real time to it. Stereo output is fine from everything else, it's just the tape that isn't perfect. There's something there, just very muted. The tapes I've been using are pre-recorded and play fine in other machines. Haven't tried recording with it yet. Was thinking probably a broken wire to the head or switch that was to blame. I've zero experience with these machines, so feel free to point out any usual suspects. __________________ Zel's Lair - A random bag of vintage tech, lighting information and other assorted geekery

24th May 2016, 8:31 pm	#6
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: B&O Beocenter 4600 Tape Deck Faulty Channel Not specific to this model, but the play/record switch in every 2-head tape deck does some pretty drastic rewiring of the internal circuitry, and just one poor contact here can cause all manner of symptoms. It's well worth a good squirt of Servisol and some vigorous exercise. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.