Sign in   |  Join   |  Help
Amazing choice of pre-owned Bang and Olufsen

Got a problem with the Forum?
then please email me at keith@beoworld.org with details

Click here to change your Beoworld Account Details

Recent repairs

rated by 0 users
This post has 183 Replies | 11 Followers

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Wed, Apr 3 2013 4:31 PM

Beomaster 3000-2
Brought to me by a fellow danish Beoworlder.
The tuning discriminator lamps were "not functioning correctly", the owner said.
True. One lamp was fully lit constantly, the other seemed to work normally.
With the lid off, it was soon discovered that some soldering had been going on in the lamp area.
Not the best job if I may say so and one of the lamp sockets had melted because of the heat from the soldering iron
so one of its pins had shorted to the metal tab that holds the socket in the set (and the lamp was stuck).
A good used socket from the dungeons was soldered in and a few other solder jobs were tidied up as well.
A fresh set of lamps rounded this job off.
Not the most difficult repair in my life but definitely one of the nicest Beomasters of this type, I've seen.
Always a pleasure to see these beautiful design pieces taken good care of.

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Thu, Apr 4 2013 8:25 PM

Beomaster 1600K
From my own collection.
A note on the set said "one channel low" 6/88.
I confirmed the symptom and also noticed that the problem was worst at low volumes.
This lead me to the loudness circuit where one of the 1,6uF capacitors fitted directly at the volume potentiometer
had gone slightly resistive (leaking current from one pin to the other).
A fresh pair of capacitors sorted it out.
The rare kind of job where you can almost tell which single component is at fault by merely playing with the radio.
I wonder what repairshop gave up on this repair back in 1988. Still it seems to be very typical to tell the customer
that parts are no longer available when the truth is the guys couldn't be bothered (or simply didn't have the skills) to
diagnose on component level.
Todays repairers will just swap modules, they wouldn't dream of doing discrete repairs to a module.
Rare birds these days, the Beomaster 1600M and K models, worth holding on to.

Martin

hemenex
Top 150 Contributor
Posts 522
OFFLINE
Founder
hemenex replied on Fri, Apr 5 2013 9:58 AM

BM6500:
Failure description: does nothing; not even standby LED lits, Fuses ok.

There has already someone been inside, shows traces of previous repair (attempts).
Rectifier D3 has one failed Diode, changed, standby restored, Radio functions ok.

MUTE inoperable.
Muting by inserted headphone ok, local key or remote: no MUTE.
A nearby Beolink7000 shows MUTE so key & remote functionable but no relay.
Mute-relay is located on a small extra PCB soldered onto PCB3.
As measureing is almost impossible while mounted this board was unsoldered. TR2 measures ok but changed anyway.
Resoldered - still no function but now one channel is missing and headphone doesn't mute anymore..
Broken trace to P6 on PCB3 fixed.
Waggling on the relay brings back channel sound sometimes.
Again desoldering shows broken or loose PCB traces on all 6 relay pins. Traces fixed and piggyback resoldered to PCB restores muting function.

Frequency display too low. Calibrating according to service manual results in correct display.

While repairing it showed generally low reception quality of remote IR-commands.
Investigation shows this to be true only while FM-listening: CD/AUX/TAPE ok, also waking-up from standby.
Changing the 2 caps in the CPU-Box was neccessary but unsuccessful.
Same with all 3 supply 100µF caps on radio PCB1.
Incidentally connecting the CPU screening metal to chassis ground enables IR reception perfectly.
Soldering a piece of wire to the box and connecting it under a chassis screw that holds PCB1 by a solder-eyelet completed the repair (up to now...).
Not sure if this connection was missing due to previous repairs or isn't implemented from factory. The BC9500 e.g. has such connection, though.

Executing its test run right now.
  Gunther (although no chance getting even close to Martin Embarrassed)

P.S. Yes, I DO like working on component level Big Smile

 

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Fri, Apr 5 2013 4:46 PM

Beocenter 7700
Brought to me for repairs by the swedish owner.
The only sign of life was the background lighting of the volume control display.
No reaction to anything whatsoever.
A quick measurement revealed that the standby voltage was missing due to a burned fuse F1.
4-ampere fuses burn for a reason and in this case the reason was a shorted capacitor on the processor board.
C96, being a 220uF electrolytic capacitor of the black Roederstein type, about the only type worse than its dreadful
red brothers, was duly replaced and so was the fuse. This brought back life to this beautiful, large, heavy and
high quality Beocenter.
New belts and a general tapedeck service was carried out too and the Beocenter was picked up a few days later.

Martin

Barry Santini
Top 150 Contributor
New York
Posts 402
OFFLINE
Bronze Member
In my next life, i want to very much be Martin's sorcerer's apprentice
Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sun, Apr 7 2013 9:29 AM

Beogram 1203
From Portugal
When pressing LIFT, a violent buzzing could be heard from inside and the deck wouldn't start.
There's not a lot of electronics in these decks and its only semiconductor was found to be defective.
A 1N4004 diode inside the starting solenoid/relay box was found to conduct current equally good in both
directions which is a definite no-go for a diode and it was retired in favour of a brand new one of exactly the same type.
A 20-minute repair but what a difference it made !

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sun, Apr 7 2013 3:17 PM

Beovox MC120.2
A nice white pair brought to me by the Copenhagen based owner who wanted me to do a
refoam job and replace capacitors.
He had also noticed an intermittent midrange, a fault that I was unable to replicate but I found a couple of
dry solder joints in one of the filter boards so that could have caused it.

Dali IV and Dali VI
Two pairs of speakers arrived here for refoaming.
The Dalis were very popular speakers in danish "HiFi-club" circles in the mid-late 1980s.
Very good quality speakers, the VI in particular, providing good quality sound and decent design at a fair cost.
Fairly small magnets and similarly small diameter voicecoils but a well-balanced sound, not
unlike Beovox S75 or Beovox S120.
Getting rare.

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sun, Apr 7 2013 10:27 PM

Beomaster 8000
This one was delivered friday evening at my door by the owner, living in northern Germany.
This Beomaster was silent on aut.tune.
I also noticed that the MPX indicator would never light up, in neither aut.tune nor manual.
A quick check with the scope revealed the "Signal condition" information on the anode of diode 2D6 to be
at a constant low level regardless of the actual tuned input.
The culprit was 2IC3, a LF353 opamp and a new part cured the fault.
I noticed the right channel cooling fin was slightly warmer than the left one and I like to fit new capacitors and
trimmers to the output stages of every Beomaster of this type on my bench, simply because the original capacitors
in these warm quarters are almost always bad or at least marginal and a bad trimmer can cause very big problems
and huge repair expenses when it fails - and that will happen eventually.
The owner, having spent the weekend sightseeing in Copenhagen with his wife, picked up the Beomaster
by me sunday afternoon and brought it with him back home.

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Fri, Apr 12 2013 9:44 PM

Beomaster 5000
80s stacking version.
Owner complained that the settings were no longer kept.
Sure they weren't. Easy-peasy, a fresh battery and off we go.
Well, at least that's what I thought but that was not the case this time !
After having spent more than 3 hours hunting down the fault on this processor module, I realized that I was "looking
myself blind" and decided to put it aside. Instead a replacement module from the dungeons was rebuilt and I
fitted a fresh battery to that one as well.
The other module will have to be be investigated with fresh eyes later but neither the CPU itself nor the two
storage ICs were at fault and all signals and voltages looked absolutely fine.
The owner wanted the Beomaster to be "pulled upwards" 20-25 years so all board mounted electrolytic capacitors
were replaced and the same was done to the idle current trimmers, the bipolar caps in the preamp section
and the muting relay.
All pretty much standard issues and the Beomaster played happily afterwards. It's not everytime I hear an actual
difference after replacing the capacitors in these wonderful stacking receivers, but this time I did.

Martin

Søren Mexico
Top 10 Contributor
Mexico City
Posts 5,962
OFFLINE
Bronze Member

Dillen:
I realized that I was "looking
myself blind" and decided to put it aside.

Thank you Martin, now I know, I´m not the only one.

Collecting Vintage B&O is not a hobby, its a lifestyle.

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sun, Apr 14 2013 2:19 PM

Beogram 4002
Type 5511
Main circuit board arrived from New York.
The owner had diagnosed the problem in a dead Beogram to be caused by "something on this board".
The board was fitted into a similar deck for diagnosing and it was clear that IC1 wouldn't open.
The cause was a shorted 22V zenerdiode D7.
The board received a handful of fresh capacitors while the soldering iron was hot, it was tested and
then escorted to the postoffice for the trip back over the pond.

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Wed, Apr 17 2013 4:28 PM

Mini Deluxe 609
From my own collection.
This one stood, wrapped in bubblewrap on a shelf, for more than 25 years with a yellowing note on it reading "Burned resistor".
Now the time had finally come to take a look at it.
The resistor in question was R52, a fairly large 2,2Kohm 2W component and indeed it was burned beyond recognition.
A short somewhere was causing the resistor to sit directly across the high voltage rail, something it wasn't exactly happy doing.
Investigating this took close to a full hour, mainly because the short came and went as the chassis was moved about
on the bench.
The large circuit board that holds the majority of components in this 60's set is held in place by small protruding "ears" bent
out from the main chassis metal. The board lies on a good handful of these and the cause for the short turned out to
be that one of these ears had worked its way into an underlying copper track on the board, shorting it very effectively to
the chassis, which represents the ground potential for the high voltage rail.
But the short was only there when the set was in normal position, standing on the bench.
The ear was bent away from the damaged area, a piece of shrink tubing added for future protection and an original
replacement resistor, taken from a chassis off a scrapped similar set saw it playing along again as if it had never stopped.
Even the dial lamps were still fine but hey, it hadn't seen use for more than 25 years.
A cleaning of the dial and oiling of the beautiful teak cabinet made it shine again and it entertained me for the
rest of the evening.
They are very nice, these Mini 609/610 sets. Their sound, compared to contemporary sets from other
manufacturers, is very much present and "alive", helped along in no minor way by the very good
built-in Philips wide-band speaker(s), no doubt.
The Deluxe models have two speakers, one each end of the long cabinet but this doesn't make them stereo as
I often see them advertized.
Mini 609 and 610, Deluxe or not, are all glorious mono with the Deluxe models showing off their two speakers in parallel.

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sat, Apr 20 2013 5:12 PM

Beomaster 3300
This one came from Belgium.
I can't really make up my mind regarding the design of the 3300 series. Some days I like it a lot, other days I wonder
how on earth they came up with something like this. Well, they are fairly serviceable at least.
Owner said this one would no longer do a thing.
He couldn't have put it any clearer. The Beomaster was playing completely dead but the amperemeter on my
B&O variac told me that the Beomaster was actually pulling some current - but about 25 Watts seemed a little high
for standby power consumption - even for a quiet idle - so apparently something was amiss.
A little poking around inside with a multimeter revealed a low 24V supply and practically a dead short on the output
of the 5V regulator IC that feeds from the 24V.
The problem component turned out to be C58, a 220uF electrolytic capacitor of the black ROE type.
I don't dare to think how boring life would be without those good old Roederstein caps, the black ones and the
red and orange ones in particular. I've replaced thousands of them.
Funny thing is that the (even older) grey types, that were so heavily used by B&O in the 60s, are often found
in excellent condition where the newer ones of the same brand are causing so much trouble.
It's not a rule that new stuff is always better, I suppose.
After a good soak testing back to Belgium it went.

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Wed, Apr 24 2013 2:47 PM

Beogram 6006
Main circuit board arrived from France for restoration.
A capacitor kit was fitted, fresh thermal paste on the processor and a good check for cracked
solder joints saw it running a fine 24 hour burn-in in the test stand.
The tangential decks of the 6006/8000/8002 series has become gradually more popular in recent years.
They are in my opinion, together with the 400x series, some of the best record decks ever made.
They are easy to use, gentle towards the precious records and their timeless design makes them a treat for the eye.
Not always easy to service, though.

Martin

IvRak
Not Ranked
Posts 18
OFFLINE
Bronze Member
IvRak replied on Mon, Jun 3 2013 6:32 PM

Great posts Martin!

I find it quite entertaining reading your findings. Its easy to read that you actually care about these products.

I'll even forgive you for forgetting my Beogram 6006 in the repairs list. Its still playing, just a couple of hours a week, and sounds very nice :)

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sun, Aug 11 2013 5:44 PM

Beocord 8004
According to the owner this one "sounded weird".
On the bench it came, connected to a freshly repaired Beolab 1700 amplifier from Italy that agreed to a couple more
hours of test, loaded a tape and pressed play.
Sound was fine and there was no smoke, so I let it run.
After 7-8 minutes or so, while moving things around and sorting some parts for another Beoworlder I thought
I heard a tiny bit of wow. I listened closer but couldn't hear any sound defects. It was very little, really nothing more
than what you can sometimes get from a very worn tape.
Surely, this could not be what the owner complained about ?
Well, I let it play to see what happened.
Not more than 3 or 4 additional minutes passed and the wow was back. Very light at first but audible in
the music and gradually, over 3-4 more minutes, it really took off and ended in a real speed chaos.
I opened the deck and noticed that the motor was not of the correct type.
It looked a recent job.
The motor was of a type used elsewhere by B&O but, being a 12V motor it doesn't work in this deck where it will be overrun.
The original motor is a 15V type with an external regulator (transistor). I dug a good used one out from the dungeons and
removed the tag on it reading "4864 7/88 OK" telling that not only was this motor tested good, it was also taken from
a Beocord 8004 back in 1988.
I gave it a light cleaning and a few tiny drops of sinter oil, fitted it and that was it.
A new playback/record relay (as is pretty much standard by now), checked the belts (looked like one of my own sets) and
after listening to great sound for hours, back to the owner it went.
I don't know how much the owner paid for the previous "repair" but apparently they haven't tested their work for
more than a few minutes if at all.

Martin

Rich
Top 50 Contributor
Orlando, Florida, USA
Posts 2,533
OFFLINE
Bronze Member
Rich replied on Tue, Aug 13 2013 5:22 PM

Dillen:

I don't know how much the owner paid for the previous "repair" but apparently they haven't tested their work for
more than a few minutes if at all.

Sad, but probably more common than not.

Great stories, Martin.

Blah blah blah, blah blah ba ran

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Wed, Aug 14 2013 8:57 PM

Beomaster 3000-2
Owner said the treble control slider didn't feel right.
While the owner was still holding the Beomaster I tried the slider, just back and forth a
couple of times and indeed it felt strange and it had a kinda "flapping" sound when it passed
the center position.
A couple of days later it was on the bench. The treble potentiometer was opened and
a brief inspection revealed one of the resistive tracks to have lifted away from the potentiometers black plastic
housing at the center.
I pressed it down with a finger but it kept snapping back up.
A quite sturdy rivet held each end as per factory but the track itself was too long to fit in between !
This was a new one for me.
The dungeons provided a good part to repair the potentiometer, a new trimmer stopped the FM presets from
flying up and down the dial everytime a button was switched and a couple of fresh lamps rounded off this repair.

Martin

tamtapir
Top 150 Contributor
Örebro, Sweden
Posts 494
OFFLINE
Gold Member
tamtapir replied on Wed, Aug 14 2013 9:50 PM

I love this thread.

/***

sonavor
Top 50 Contributor
Texas, United States
Posts 2,762
OFFLINE
Gold Member
sonavor replied on Wed, Aug 14 2013 10:00 PM

tamtapir:

I love this thread.

/***

Yes, this thread is becoming a nice "cookbook" of things to check on vintage B&O equipment.  Thanks Martin and keep the information coming.

Puncher
Top 10 Contributor
Durham
Posts 11,217
OFFLINE
Founder
Puncher replied on Wed, Aug 14 2013 10:10 PM

First time I've happened upon this thread but, ................. absolutely brilliant!!

A valuable resource as it builds, as many faults are really common in given models but (and this is a bit sad), I like to read about issues being discovered and overcome, even in equipment I don't even own!!Embarrassed

Ban boring signatures!

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Wed, Aug 28 2013 9:24 PM

Thanks for all the comments. Greatly appreciated !
I'd only wish, I had time to do writeups of all the repairs I do but my time simply doesn't allow for this.

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Wed, Aug 28 2013 9:26 PM

Beomaster 5500
Third one in two weeks and months since the last one. Funny how repairs to some models seems to come in waves.
This one came from France with a note saying "Speaker set 1 no sound".
OK, so another dead muting relay.
Wrong! The relay didn't even click when mute was activated.
A quick voltage reading revealed the relay to be powered all the time.
Another quick reading, this time continuity across the relay driver was checked and, sure enough, a dead
short was found.
So a shorted transistor then ?
Wrong again! The transistor measured fine when desoldered and the short remained in the circuit.
Time to bring out the manual. Oh, the headphone jack! When headphones are connected speaker set 1 is
automatically muted through activating the relay and with this type of headphone jack, accepting the slimline 3,5mm
jack plugs I've once before found the remains of a broken plug in the socket.
But not this time. The socket was completely empty - but permanently shorted.
The dungeons provided a good used replacement part, the muting relay was replaced and to counter for
future trouble with other known problems the idle current trimmers and the capacitors in the output stage and
in the voltage regulating circuits was replaced and adjusted as per factory specs. They are cheap components
and fairly easy to replace so worth doing, particularly in a unit that has travelled far.
A good soak testing and back it went.

Martin

Stonk
Top 50 Contributor
Marlow, Bucks, UK
Posts 2,060
OFFLINE
Founder
Stonk replied on Wed, Aug 28 2013 10:50 PM

Ditto. Great thread. Who was that guy in the US that used to do the same? Had an AOL webpage with familiar repair stories. After he went AWOL I was pleased to find Beocentral's version and now that Martin has started doing them its fantastic, even to someone who's main tool is a hammer!

If you think nobody cares, try missing a couple of payments.

Piaf
Top 50 Contributor
Victoria, British Columbia Canada
Posts 2,529
OFFLINE
Founder
Piaf replied on Thu, Aug 29 2013 2:00 AM

Hello Martin,

 

I wish to add my kudos to your excellent thread. I made the concerted effort to read the entire collection with two results: First, I am exhausted, and second, I will never complain about any of my B&O gear ever again.

 

Jeff

Beogram 4000, Beogram 4002, Beogram 4004, Beogram 8000, Beogram 8002, Beogram 1602. Beogram 4500 CD player, B&O CDX player, Beocord 5000 T4716, Beocord 8004, Beocord 9000. Beomaster 1000, Beomaster 1600, Beomaster 2400.2, Beomaster 2400.2, Beomaster 4400, Beomaster 4500, Beolab 5000, Beomaster 5000, BeoCenter 9000. BeoSound Century,  S-45.2, S-45.2, S-75, S-75, M-75, M-100, MC 120.2 speakers; B&O Illuminated Sign (with crown & red logo). B&O grey & black Illuminated Sign, B&O black Plexiglas dealer sign, B&O ash tray, B&O (Orrefors) dealer award vase,  B&O Beotime Clock. Navy blue B&O baseball cap, B&O T-shirt X2, B&O black ball point pen, B&O Retail Management Binder

 

MediaBobNY
Top 75 Contributor
Greenwich Village, NYC
Posts 1,030
OFFLINE
Founder

Stonk:
Who was that guy in the US that used to do the same?

Anthony Garza in Texas?  BeoMuse?

Søren Mexico
Top 10 Contributor
Mexico City
Posts 5,962
OFFLINE
Bronze Member

I´m Martins pupil, I want to be the new Martin, so I´m reading everything on this thread, Will i become as good as Martin ?? I dont think so, probably I´ll die trying Laughing.Keep them coming Martin, I really enjoy this.

Collecting Vintage B&O is not a hobby, its a lifestyle.

Piaf
Top 50 Contributor
Victoria, British Columbia Canada
Posts 2,529
OFFLINE
Founder
Piaf replied on Thu, Aug 29 2013 6:48 AM

Søren,

 

You are an excellent pupil and what you attained with your Beomaster 4400 is beyond remarkable. You achieved the virtual impossible and all the while kept us all riveted to our computer screens. I’ll bet there were several American TV series that had lower ratings than you this year!

 

As far as becoming the new Martin, there is no need to compete with Martin, the class act of Denmark. That Martin is a Bang & Olufsen maven goes without saying. That you are a self-taught version thereof is simply a testament to your learning ability and Danish determination.

 

İVia con Dios! Smile

 

Jeff

 

P.S. Not to worry, I am not overly religious, I just love to use the limited Spanish I remember from high school, 150 years ago. İTú eres mi héroe! Yes - thumbs up

Beogram 4000, Beogram 4002, Beogram 4004, Beogram 8000, Beogram 8002, Beogram 1602. Beogram 4500 CD player, B&O CDX player, Beocord 5000 T4716, Beocord 8004, Beocord 9000. Beomaster 1000, Beomaster 1600, Beomaster 2400.2, Beomaster 2400.2, Beomaster 4400, Beomaster 4500, Beolab 5000, Beomaster 5000, BeoCenter 9000. BeoSound Century,  S-45.2, S-45.2, S-75, S-75, M-75, M-100, MC 120.2 speakers; B&O Illuminated Sign (with crown & red logo). B&O grey & black Illuminated Sign, B&O black Plexiglas dealer sign, B&O ash tray, B&O (Orrefors) dealer award vase,  B&O Beotime Clock. Navy blue B&O baseball cap, B&O T-shirt X2, B&O black ball point pen, B&O Retail Management Binder

 

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sat, Dec 7 2013 12:27 PM

Beomaster 700K
This one arrived from Japan where it had been in daily use on the bedroom sidetable for more than 15 years.
It had never had any repairs and never gave any problems before but now, after 40+ years, it had reached a point
where service was needed - deserved and granted - since reception was now intermittent and the dial light went out years ago.
No local repairers were willing to take it in for service so the owner asked if I would agree to take a look at it.
How could I say no ?
A fresh pair of dial lamps and a good cleaning of the dial backside saw the dial lit up nicely again and a
fresh pair of IF transistors brought back FM reception.
A noisy AF transistor that made a constant hissing sound came as no surprise and a new AC151 cured the problem.
The teak cabinet was in pristine condition but a little dry so received a light coat of teak oil and a careful rubbing with
very fine steelwool to bring back the original silky gloss.
The speaker grill was missing and I asked the owner if he just chose to keep it at home, but that was not the case.
He was very sad that it had gone missing many years ago and he was sure that a replacement was nowhere to be found.
Well, maybe he sent it to the right place after all; The dungeons could provide a good original part, a little digging around
even left me with the choice of three or four different shades of fainted and/or sunbleached grey shades.
The best match to the color and aging of the still-in-place dial frame was chosen and the grill was fitted, allowing this poor
thing to feel complete and look intact again.
A zipper bag with yet a pair of correct dial lamps was fastened inside the set in agreement with the owner together with
an original envelope containing the circuit diagram for this model. The latter was missing and I happened to have one from
a set that was scrapped years ago. The original schematics could provide valueable information for the next repairer and
they somehow feel like part of the set.

A couple of evenings testing and back around the globe it went.
Not a particularly special repair, all very common really but they are wonderful radios, those Beomaster 700Ks.
Tuner, amplifier, speaker, antenna - all in one, just plug it in, switch it on and play.

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sat, Feb 1 2014 8:58 PM

Beolit 1000
A local owner brought this little beauty to me for repairs together with a Beocord 1600 open reel deck.
I don't see too many of either and I gladly accepted them in.
He actually restored the radio himself, polished metal parts, oiled woodwork and all. Looks a more than decent job and
a really nice radio.
However, the dial string for the FM tuning had come off or snapped at some point and some readers will know that
stringing a dial with all the pulleys, wheels, springs, dial pointer and capacitor, let alone getting things to move, slide and
rotate the right way around can be a headache.
Well, it didn't keep this owner (or a previous) from trying his luck though; Inside I found the remains of a failed attempt in
the form of a piece of dial string connected to "something" at one end and nothing related at the other.
Beoworld surfers who know me will also know that I have a huge respect for owners wanting to have a go at
repairing or restoring things themselves. It's a wonderful hobby but, having said that, I have an even deeper respect for
DIY'ers who, when they realize that they are in too deep, turn over the task to someone else.
It took me a good two hours before I got it right but what a rewarding feeling. This is one nice radio, classic design, beautiful
and well sounding. No wonder they are so sought after today.
To tell the truth, this one wasn't particularly well sounding, which also was the other issue pointed out by the owner.
"Can you check the speaker too, please?", " It doesn't sound right all the time".
Yeah, no wonder. Its magnet and the entire area around the spider was stuffed to the limit with steelwool debris...
It's always a good idea to keep woodwork about to be "steelwool'ed" away from magnets, particularly speaker magnets.
Circuit boards etc. are no good near steelwool debris either.
I managed to remove most of the little stray strands by carefully poking around the affected areas with a tiny
screwdriver connected to a very powerful magnet to persuade the little steel buggers to come with me rather than just
hang around the speaker spider.
I couldn't remove everything. I think, one or two tiny pieces of debris had found their way through the dustcap material and
into the tiny gap between the coil former and the magnets center piece but it's not very audible and the debris may end
up being pushed out of harms way with use. I hear no problem when playing anyways.
A very beautiful piece and a pleasure to know that it will see daily use.

Martin

Piaf
Top 50 Contributor
Victoria, British Columbia Canada
Posts 2,529
OFFLINE
Founder
Piaf replied on Sat, Feb 1 2014 9:16 PM

Hi Martin,

 

By now your workmanship and tenacity are legend here at BeoWorld and rightly so.

 

With your eye for detail nothing gets missed and a repair by you stays repaired.

 

Please feel free to take a small bow for this well earned kudos!

 

Jeff

Beogram 4000, Beogram 4002, Beogram 4004, Beogram 8000, Beogram 8002, Beogram 1602. Beogram 4500 CD player, B&O CDX player, Beocord 5000 T4716, Beocord 8004, Beocord 9000. Beomaster 1000, Beomaster 1600, Beomaster 2400.2, Beomaster 2400.2, Beomaster 4400, Beomaster 4500, Beolab 5000, Beomaster 5000, BeoCenter 9000. BeoSound Century,  S-45.2, S-45.2, S-75, S-75, M-75, M-100, MC 120.2 speakers; B&O Illuminated Sign (with crown & red logo). B&O grey & black Illuminated Sign, B&O black Plexiglas dealer sign, B&O ash tray, B&O (Orrefors) dealer award vase,  B&O Beotime Clock. Navy blue B&O baseball cap, B&O T-shirt X2, B&O black ball point pen, B&O Retail Management Binder

 

Christian Christensen
Top 150 Contributor
Stockholm
Posts 512
OFFLINE
Silver Member

I bow
I am honoured to have your help, Martin. 

Christian 

My re-capped M75 are my precious diamonds.

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sun, Feb 2 2014 9:15 AM

Beocord 1600
The open reel model.
Came in together with the Beolit 1000 mentioned above.
This one "wouldn't run right".
A brief test showed that the take-up function was pretty much non-existent.
The capstan and pressure roller pulls the tape from the left (supply) reel over the tapeheads and it's
then the right reels task to take up the tape that has been played. It is motor driven through a felt-pad type of clutch
to provide a very delicately balanced torque;
Enough to take up the tape, even with an already almost full reel on the spindle (large diameter pull)
but not too much or it would pull the tape through the capstan/pressure roller, resulting in wow and, in severe cases,
a stretched and damaged tape.
In this little well-preserved deck the round felt pad had come lose. Just sitting there sandwiched between the motor
drive plate and its teflon covered counterpart it didn't do its job right.
In an attempt to make it work again, someone had tried to adjust the related springs tension
and when that didn't work, a shot of WD40 or some other nasty agent had been sprayed onto the felt.
Of course, adjusting blindly and/or in panic doesn't work and I've yet to see WD40 do much good in any stereo whereas
I find it very good in the garage for losening rusty bolts on my old cars.
WD40 contains a large amount of silicone, what a mess to get in a felt clutch. - And almost anywhere else.
I took the thing apart, cleaned the felt in silicone remover and acetone and let it airdry outdoors for a couple of hours while
I cleaned up a couple of other things and added a tiny drop of oil to dry spots here and there.
Finding badly aged belts in the good old Beocord 1200 and Beocord 1600 open reel decks is very common and I usually
replace them on sight but the ones in this deck looked absolutely fine. No reason to replace anything just for the
sake of doing so.
Glued back the felt pad, put it all back together, adjusted the tension of the friction plates spring, cleaned the
tapeheads, guides, capstan and pressure roller.
I also glued back the square piece of double insulation sitting inside the rear cover, also very common to find
this rattling around inside.
Brought it back to my livingroom, connected it to my Beomaster 8000, fitted a tape and let it put out lovely 1980s music
for the rest of the evening.
I always had a weak spot for the Beocord 1200/1600 design (Jacob Jensen). Lovely decks and not too difficult to service.
B&O produced open reel decks with way better specs and loads more functions years before this series but
the Beocord 1200/1600 is really not THAT bad either.
It has all the functions you will need in daily use. It also has a more modern look and with that a potentially
higher WAF compared to its older brothers.
Place it side by side with a Beogram 1203 or similar record deck and put a Beomaster 3000 on the shelf below and you'll
have a beautiful and timeless stereo system.
The Beocord 1600 even has a built-in stereo output amplifier so to play music, you would just have to connect a
pair of speakers.
And they are getting rare.
Worth picking one up if you collect B&O or just happen to like hearing music while watching those reels rotate.
If you can find the original wheel stand too, you can consider yourself extremely lucky.
- Or the wall bracket... An open reel deck wallmounted, how cool was that...

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Tue, Feb 11 2014 7:24 PM

Beolab 8000
Hand-carried, very carefully, to me by the owner.
I haven't serviced a lot of the "newer" things, I like to focus on repairs to the older audio things, typically pre-1990 where
B&O and many others no longer provide any support but, having said that, just this once in a while something
catches my interest and it happened with this poor thing.
The owner said the LED was nice and red in standby and equally nice and green when activated - there was
just no sound.
In other words; All the fancy stuff seemed to work - it was just not performing the finest of speakers tasks - namely providing sound.
Up with the bonnet and have a look at the engine. Measure around a bit here and there and it was soon clear that
the connector to the relay/transformer board only had one of its two pins actually electrically connected to the relay coil.
A broken copper track was the reason. I couldn't spot the break but a short piece of wire sorted it, nicely glued
to the board to avoid rattling while playing.
Put it back together, connected a CD player to the Phono plug - and I had music.

- And red light...

Hey - red light and music is maybe not quite as wrong as green light and no music but it's still wrong!
A couple of long leads soldered to the relay contacts proved to me that the relay was powered all the time.
So the thing would now never power off the amplifier, despite the constant red light.
Moving the leads to the base and emitter of the relay driver transistor provided proof that the thing was actually
trying to switch the amplifier on and off and at the right times - it just couldn't.
Only possible culprit was transistor TR11, the relay driver.
Lacking a BC847C SMD component, I fitted a normal TO92 housed BC547C for two reasons;
1. It happens to be the exact same component as the original, just in a different, larger, housing.
2. I had one in the drawer.
There was just enough room if I placed it close to the board.
Put the thing back together, played a CD or two and all was fine.
Standby red. Playing green.
And best of all; Sound when expected.

What a classic and beautiful speaker this is.
And what a mess those foam thingies inside make, it's all over, on your fingers, elbows - everywhere.
Fortunately, most will wash off in cold water. The rest is removed using IPA.

Martin

Aleksei
Not Ranked
Russia
Posts 30
OFFLINE
Bronze Member
Aleksei replied on Wed, Feb 12 2014 7:31 AM

Just recently fixed the nice BeoCom 2000 unit.

It took some time to find out that the problem is the internal break in the handset speaker. Since this is 100 Ohms, that was not available in the local shops, so I had to turn to ebay. The replacement went Ok, though I had to cut the rubber ring around the speaker (the new component was not the same p/n).

The result is awful because:

- now there's a annoying sound feedback sound in the potentioneter position farther than 50%. Probably, new speaker is a bit louder.

- the handset was one-piece, so I had to carefully break it along the welding line, and glue back with epoxy.

It works, but I cannot be proud of myself :(

 

https://beointegration.wordpress.com/

Beobuddy
Top 25 Contributor
Utrecht, The Netherlands
Posts 3,204
OFFLINE
Founder
Beobuddy replied on Wed, Feb 12 2014 12:45 PM

@ Dillen.

The malfunction of the BL8000 is caused by the old foam. I assume you removed the sticky stuff? 

I recently have had several BL3500's, also problems with old foam which can cause shortcircuits, broken traces behind the display and so on.

Not to mention the next thread, leaking SMD capacitors. Also several removed (a very smelly business) with broken traces underneath.

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Wed, Feb 12 2014 1:03 PM

Thanks, yes, I removed as much as the sticky stuff as possible, it was no longer doing any good anyways, and I also wondered
if it could end up causing problems if left in situ. It seems to collect moisture, which at the same time breaks down the material.
What a mess!
However, the copper track in question was in a clean area without foam debris so I don't think I can blame it for this fault but I could easily imagine
that this foam could cause problems for many Beolab 8000 owners in the coming years.

Martin

Beobuddy
Top 25 Contributor
Utrecht, The Netherlands
Posts 3,204
OFFLINE
Founder
Beobuddy replied on Wed, Feb 12 2014 1:09 PM

It definately will be cause many future mal functions. These traces are placed on the edge of the circuitboard where the old foam "touches" the board with probably more pressure.

I've had one last week with a broken trace, which couldn't be seen by the naked eye. Only measured.

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Wed, Feb 12 2014 1:18 PM

Beobuddy:

It definately will be cause many future mal functions.

We'll be ready! Laughing

Martin

Dillen
Top 10 Contributor
Copenhagen / Denmark
Posts 9,627
OFFLINE
Founder
Moderator
Dillen replied on Sun, Feb 16 2014 2:57 PM

Beocord 5000
After spending a good week in danish customs, who had a hard time understanding why someone would go this
distance to have an old 1980s cassettedeck repaired, this fantastically well-preserved 1980s unit arrived from Israel a
couple of weeks ago.
Yes, I have a little backlog due to my normal 8-5 job taking a lot of my spare time.
This unit had a note on it saying "Weak recording right channel".
I took the lid off and looked inside.
Took out the datalink pins from the DIN on the captured signal cable and plug'ed it into my B&O TG7 signalgenerator.
Loaded a tape and pressed record. Tuned the TG7 to 1KHz and put the scope onto the record current trimmers, I find
them a most convenient place to check what's going to the tapeheads. Everything looked fine in both channels.
That was when it struck me to take a look at the tapeheads...
I have seen a lot in my time but never a tapehead this dirty. It took five double-ended cottonbuds and an ocean of
isopropanol alcohol to make them shine again. I even had to remove a tiny particularly stubborn piece of gunk using
a fingernail.
But what a difference it made. Clean recording, clean playback.
The owner agreed to let me replace the record/playback relay and the belts while at it. This is well worth doing,
especially in a unit a long way from home.
I also replaced a broken rubber foot.
The later decks, Beocord 5500 etc. all have autoreverse and even if it actually works very good, they really struggle
to compare to the quality of the Beocord 5000. Producing clean recordings and good sound everytime, it's just
a very sturdy and stabile build that simply works.
Electronic faults are rare, even after 25+ years.

Martin

Page 2 of 5 (184 items) < Previous 1 2 3 4 5 Next > | RSS