yes I am very interested, and I did not get your email address here to contact mine :
stephane.kiene @ free.fr

Stéphane

email sent

Hi all,

Sorry, this is a 5 year old thread, and I'm a newbie, although I have been in love with B&O products since the mid-70's. :)

I just got a Beogram 6000 Typ 5502 together with a Beomaster 6000 Typ 2702 and ran into some problems within 24 hours...(/yes, I am a quad fan, and I may use some sensible upgrades/modernisations, although I am after a "period sound" as I do have also modern DTS/5.1 systems and Involve Audio's Surround Master for SQ/QS etc.)

But I am not easily scared off, I am just having a hard time figuring out what's the problem with the Beogram power supply. Judging from what I can see and measure, it's an AC version.

What I am getting at the moment, with a multimeter is:

100V AC across the 0.25A fuse holders.

 0V AC across the red and black wire entering the large capacitors (2 x 4000 µF 50 v.DCW, Type K1 Black Negative XHA)

13V AC across the Right Hand side fuse and both terminals on both large capacitors

 0V AC across the Left Hand side fuse and both terminals on both large capasitors

 0V AC across any of the connectors and the Beogram alu body

Anyone know what the voltage at the capacitors should be? Or any resistance I should measure between any of the connections?The weird part is that I get absolutely no voltage accross any of the connectors on the 13-pin connector to the main board.

Martin's quote "They short on the primary" could be my case, but if so what's the solution? Take the power supply out and have it refurbished?

But is it ok, if it gives a steady 100V AC and the problem is elsewhere? (I am more used to failed capasitors with 40+ year old electronics, but so far I only have experience in the CD world, not AC. :)

Cheers!

Pekka T.

Obviously, there should be no AC voltage to speak of after the rectifier.
And measuring from a point on the transformer primary to a point on the secondary simply doesn't make sense. Let alone if the latter is
after the rectifier.
Do you understand the basics of transformator, rectifier and filter capacitors and how the circuits work? If not, I strongly suggest you
leave servicing to someone with the education and knowledge to do it. For your own safety and for that of the Beogram.

Martin

Hi,

Yes, I have no intention to repair or solder any components on this device myself.

But the problem is that shipping a device like this is both risky and expensive (I paid 1.100 DKK, ca. €150 EUR just for the shipping box and freight) I would rather ship or have repaired just the part which is faulty. Soldering any wires back could easily be done locally, by an experienced workshop.

I do not know what is a "rectifier" but I can find out. To me it looked more like there would be both AC and DV powered 4002 and 6000 models depending on model and year of make. But I am a newbie and likely wrong in many areas.

The Beogram 6000 was working beautifully, but for less than one day. It stopped in the middle of playing a record. I replaced one burnt fuse (the Right hand side fuse if it plays any role) and plugged the power cord back in which kicked the surge protection on the extension cord. I then unplugged everything and just started to check what's what.

I also have very weird DC and AC voltages on the Beomaster 6000 Typ 2702 that the Beocord 6000 Typ 5502 was connected to at the moment, but not on the PHONO4 DIN-5 connector, only on the AUX2 and TAPE4 inputs. But Alain from Belgium is helping me with that as that unit had been serviced and repaired by him less than 18 months ago. However he has not had anything to do with this Beogram 6000 which I bought from the same (Danish) dealer as the Beomaster 6000. I did not know about them but started to measure different voltages across different components just to be safe and to try and figure out where the problems are.

So why I am asking this is that instead of a "complete repair and restoration" I could perhaps just have one key component(like the power supply) replaced or repaired and all would be good. All the light bulbs, all buttons and all automatic functions (except I could not really test the CD-4 as I have (yet) no Quadradiscs or CD-4's) including automatic speed changes etc. worked 100%. But the unit just went dead in the middle of playing a record. (Sibelius' 6th Symphony wth the Bournemouth orchestra conducted by Paavo Berglund in SQ) and changing the fuse did not help. Oddly enough if the fuses are there to protect the equipment I don't know why the first fuse burned, but the ones there now (all of the suggested 0.25A 250V value) do not burn when connected. Because some component failed, shorted out and is no longer conducting electricity?

I have seen cars which were "broken and complicated" that only needed one small inexpensive component in the ignition circuit fixed and ran like new after that. Sent to "complete restoration" it would have taken months or years and cost a hundred thousand euros or more.

Yes these are complicated devices, but I honestly think there can be simple solutions once we know what's wrong.

So in my case it looks like:

a) the rectifier is toasted

b) the power supply has failed, in one way or the other

I may get to the transformator later, my electrical vocabulary is mostly in Finnish (the language I learned physics in) so until further I will have to translate a few words to know what we are talking about. Sorry for that. :)

Do you know any really good Beogram 4002 / 6000 Typ 5502 specialist in Helsinki? I'll give him a call ASAP.

The ones I have found so far are in Tampa, Florida and Israel. :)

Pekka T.

HI again,

I did some reading and translating of terms. :)

So please allow me to rephrase the question(s):

Is the normal voltage going into the transformer 100V AC?
(that's what I have after the voltage selector at the fuses)

So I think my problem is the transformer as I can not measure 25 VAC coming out of it, it's giving erratic values.

The rectifier is giving out 0.36V DC when I believe it should be giving out ca. 30V DC.
I can test it with a power supply to 25V AC and see if it works ok.

I have the schematics now.

Pekka T.

All Beograms are AC powered.
"DC and AC versions" merely points to the platter motor type being either AC phase-controlled or DC servo-controlled.

The power supply is not just "one component", it's a circuit consisting of the mains transformer, the rectifier, filter capacitors and
voltage regulators. Part of this is on the main circuitboard, the rest fitted on the chassis. 

If you are in Finland, your mains is not 100V AC.
In Europe mains is 220-240V
If you measure 100V AC with your meter across your mains in Finland, your meter is not working (or you are not using it right).

Martin

Pekka

I have received your request for help.

Of course I can take care of it, but I believe that the problem is NOT on the PCB, but further in the machine itself, so even if you sent me the PCB, and I overhauled it to completely new condition, then as soon as you operated it again, the PCB would burn again.

So it must be examined as a complete machine, and NOT as only the PCB.

I would start by looking at 2 areas, which draw high current - the DC motor which moves the arm to the left or right - if there is some obstruction to the movement there, and also the solenoid coil which drops the tonearm, which should measure a minimum of 9 ohms.

The input to the transformer at 100V - completely unreasonable - aren't you in a 230V country? 

Check your Multimeter.

The only other man in Finland whom I would trust is Mika - known here as tournedos.

If there is any other way I can help, feel free to ask.

Regards

Menahem Yachad

Are you sure, you are not measuring across only one of the primary transformer windings?
Depending on the exact version of Beogram, that would make sense at around 100VAC.

In some decks, the fuses are in series with each a primary winding and measuring across them won't make much sense.
Check the schematics with regards to the fuses positions in the circuit and make sure, you are measuring the right places. 

Martin

Menahem Yachad wrote:

The only other man in Finland whom I would trust is Mika - known here as tournedos.

No pressure on you, Mika, for being know as the only trustworthy man in whole Finland 😂 I do hope this was meant to be as in B&O-related technical matters...

Pekka, I'd suggest you contact a shop like http://www.classicaudio.fi and ask them for help or to point you to a nearest repairman. I know they have at least one B&O-specialist whose services I have used myself and I am sure you'll get someone to have a look on your Beogram.