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,I have 1 beogram 4002 with the power supply / transformer death. I found one power supply / transformer beogram 4000, is that I can use? does it have to do something special?thank you
They have different part numbers - but they look very similar! What type of BG4002 do you have?
Peter
my Beogram 4002 type 5501, the problem is that on my Beogram it there's two blue wire coming out of the transformer but the transformer I found it there's over 6 coming out in dc: two black wire , 2 red and 2 yellow ...
Stéphane
They are not interchangeable.But many people are looking for working BG4000 transformers so you can easily part with it again. I know that "strong forces" are currently working on a solution to the BG4000 transformer problem.
Martin
Contact fellow member Menahem, he knows someone that can re-wind B&O transformers.
Derek
thank's for your answers, I'll actually see a transformer rewind....
regard's
Martin,
What's the BG4000 transformer "problem"?
Menahem
I actually have a working Beogram 4002 Type 5513 transformer laying around if you are interested
Vinyl records, cassettes, open reel, valve amplifiers and film photography.
hi Soren,
thank you for your offer but my Beogram 4002 is 5501 type ; it is AC powered while on your Beogram, the motor is DC powered.
It's a pity
Stephane
Hi Menahem
The power of my Beogram 4002 is dead, I have a power supply for Beogram 4000 (My Beogram 4002 Type 5501 is supplied with AC output transformer as Beogram 4000).But I do not know what I should have voltage output power on my 4002 because the transformer is dead, I just do not measure ... On the plans, I found voltage but come after the diode bridges as they are low and I do not think it is good value.I need the secondary voltage of my Beogram 4002 TYPE 5501 for adapt the transformer 4000.thank you for your information
Menahem Yachad: Martin, What's the BG4000 transformer "problem"? Menahem
They short on the primary.
OK, nice to know - I haven't had that problem on any of the ones I've serviced.
Anyway, there is always the option of the workshop in Tel Aviv which rewinds these C-cores with no problem.
Anyone who wants this done, is welcome to contact me - I offer this as a service only, and put you in direct contact with the technician.
Hi,
I don't have a BG4000 or 4002 here right now to check. Nothing is in my notes about it, but lately I have decided to write down inductance and resistance on all future transformers I work on, so I will have a reference if I have any troubled ones in the future.
I have not had any BG4000 or 4002 transformers fail, but other B&O transformers have failed, and I have had this workshop do the rewinding. The tech is very familiar with B&O C-core transformers, and his excellent results show.
Now, I will give you some numbers from my memory, but I do not guarantee them. I remember on the BG4002AC that the voltage immediately after the bridge rectifier should be about 41VDC, with the turntable at rest.
The voltage drops as soon as you push any buttons.
That voltage is basically the AC rectified. If you have that, your transformer is fine. If not, you have a problem in the transformer or your control circuit is not OK. You can easily disconnect the control circuit to eliminate that as a possible cause.
Unfortunately, I cannot give you any more information about the voltage in that part of the circuit.
A shipment France / Israel and the price of the repair may cost me dearly, so I would try to be sure Beogram before he did anything else ...voltage of 4000 I can measure because the transformer is good that this problem is to know the output voltage of the 4002-type 5501 (this is the same as the 6000 Type 5502). what's crazy is that this voltage is indicated on the manuals nowhere and nobody knows ...Circuits after diode bridges appear on the 4000 are voltage 50v to above, another 15v and the other has nothing indicated.The diode bridge circuit after the 4002-6000 shows 22.8 vso it seems to me that the transformer 4000 is more powerful than I would get resistances may be necessary to obtain the voltage ... I'm going crazy with this unit
Question: (maybe stupid) Is it possible to connect a variac AC to the bridge rectifier OD1, then slowly increase the voltage until the 41 V DC after the OD1 is reached.
With the BG in off and the 80 mA fuse out, then check the AC voltage on the variac.
Collecting Vintage B&O is not a hobby, its a lifestyle.
Søren Mexico: Question: (maybe stupid) Is it possible to connect a variac AC to the bridge rectifier OD1, then slowly increase the voltage until the 41 V DC after the OD1 is reached. With the BG in off and the 80 mA fuse out, then check the AC voltage on the variac.
Yes, it's possible. But be careful.
yes I'll see if I can find a variable power supply ..I'll let you know when I have new
Just been talking to Tim Jarman and he would be very interested in the 4000 power transformer. He would get you a suitable transformer for your 4002 in return. Email me if you are interested.
yes I am very interested, and I did not get your email address here to contact mine :stephane.kiene @ free.fr
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 isafter the rectifier.Do you understand the basics of transformator, rectifier and filter capacitors and how the circuits work? If not, I strongly suggest youleave servicing to someone with the education and knowledge to do it. For your own safety and for that of the Beogram.
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. :)
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.
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 andvoltage 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 220-240VIf you measure 100V AC with your meter across your mains in Finland, your meter is not working (or you are not using it right).
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.
Menahem Yachad: 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.
"the only trustworthy man in whole Finland "
Loved that!
Yes, in B&O technical.....
lausvi: 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.
sure, I was there yesterday and today! (I live nearby)
I had been looking for a Quad amp and/or possibly a CD-4 capable turntable (record player) for some time. I would have gladly bought locally, especially for this kind of problems. Now I bought from a dealer (in Denmark, where else) and he seems to know his stuff, but still this happened. :(
It did not work even for 24 hours, with Classic audio (I bought an Akai GX-630D-SS from them and a bunch of vintage speakers) I would have a complete one month warranty.
here the problem is that this is a complex devoce that was working 100% pergectly before it shut down. Why could it not be just the Power supply / Transformer? (Sorry for short, and strange typing, darn iPad, good for reading, BAD for writing...)
Menahem Yachad: Pekka I have received your request for help. 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
Thanks. I will look into these and take measurements. The motors seem to move freely, I can test them too. I had to move the arm to get the disc out, as it had stopped in the middle of a record. I could quite easily rotate the wheels to slowly roll the arm back.
Yes, I have several multimeters, and this is the best of those. I use them on DC stuff (car electronics) quite a lot. The wall socket and extension cord with power surge protection show 230V AC. That's why I asked about the transformer voltage originally as I did not know what happens inside the voltage selector switch housing etc. Now I have complete schematics and can see what's supposed to happen and where.
I suspect some shorting or leak to the ground as the other fuse terminal (the right hand side, the one that burned) shows almost 14V AC to about all terminals found anywhere inside the Beogram. Including the connectors for the audio output socket, where I can measure 13.9V AC between the ground connection and the mentioned RH fuse and 12.5V AC between all four channels and the fuse.
That's why I was so confused about the whole voltage issue and started thinking the whole thing operated with AC! :D
But my logic would say the transformer has a short to the ground of the whole and thus I can measure AC voltage across anything and the fuse holder.
Yes, I agree, fixing a board and putting it back in a situation where there is unwanted voltage across the whole board or the whole casing is not something I would do either. That's why I want to find out more and once all places show correct connections and correct voltage then the damage can (hopefullly) be repaired.
If you bought from a dealer (shop/business), the unit comes with a certain warranty.In that case, I suggest you contact the dealer.
Dillen: If you bought from a dealer (shop/business), the unit comes with a certain warranty.In that case, I suggest you contact the dealer. Martin
Hi Martin,
I did. And of course I contacted him immediately and told him in great detail, how the wooden shipping box had lost one "leg" but the box itself was intact, everything inside was absolutely fine, complimented him on great and careful packaging (the lid for the Beogram 6000 has on one crack in a corner, but that may have been there for decades) especially the cartridge and needle that had extra padding and taped together over the regular protection cover for the cartridge and needle.
I also told him how I let the box get warn first in our office (21.9°C) and also several hours after opening the wooden shipping box and only then when everything was room temperature I mounted the equipment on a steady, good table surface and then plugged in the cables and switched the power on etc.
I also told in great detail what I did and what happened, how the Beogram just stopped suddenly in the middle of playing a record and how I replaced (carefully) the 0.25A 250V fuse and how then it triggered the power protection on the extension cord (and other equipment also went down, except my laptop as it was then running on it's battery) That is also why I started to measure all connections as it seemed there was indeed an electrical problem.
I do not wish to have the Beogram shipped back and forth, I will do it of course if I have to, but like I wrote, it cost me ca. €150,- euros (1.100,- DKK) just to get it here. If we have to ship it back and forth, there's always the risk of further damage AND it will cost worth the unit itself just to get it shipped there and back etc.
I did get a response from him and did get in touch with Alain who has serviced/restored the Beomaster 6000 Typ 2702 and got a PDF about the details of the restoration (looks like really good work) and other material. That unit had from start when it arrived in my office, a rather disturbing buzz in the Left rear channel, and still has whenever the Rear speakers are switched on, regardless if there's signal or not. And all three other speakers, incl. Right rear, sound fine, but this Left rear just keeps buzzing and does not produce any other sound. Now that might be the case of another thread or discussion, but for now I AM trying to solve that between the Danish dealer who sold me the whole lot and Alain who had restored it and me.
But for this Beogram 6000 Typ 5502 Alain has nothing to do it, it too has been serviced at some point (one screw missing from one of the boards, and it was not loose inside the housing. Yes, I would like to have it working again, but no I would not like to ship the whole unit, unless the dealer pays the shipping, which I think may be unlikely. If I just return it, I would loose the wooden shipping box (could be handy for shipping another Beomaster 6000 Typ 2702 for restoration) and the shipping cost one way (anything between €50,- and €100,- euros I think one way) and possibly then I would not have a Beogram 6000 wityh a CD-4 demodulator anymore, which is what I wanted in the first place.
Sorry for this much explaining, but I thought maybe you did not realize that doing this checking myself and seeking help from the beoexperts and beolovers was kinda my last chance, ok?
Cheers,
Dillen: If you are in Finland, your mains is not 100V AC.In Europe mains is 220-240VIf 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
Thank you for pointing that out. And like also pointed out, that was really odd.
That's now fixed. :)
Perhaps this would explain, why the unit was set to 220V although it came from Denmark, where I believe they also have 230V AC 50Hz like we do. LIke you all kept telling me that it should read 230V AC and doubted my tools and my knowledge it turned out to be the voltage selector. I opened it and then measured the voltages again. Yes, input cord obviously had 230V AC just like the wall socket and extension cord, BUT the other connection for the voltage selector only showed 100V AC. I switched it back to the 220V setting and now I have 230V AC on both terminals and both fuses. About 232V or 233V to be more exact.
So one problem down.
But the rectifier still outputs ca. 0.5V DC instead of 25V DC and the input /the two thin black cables show erratic AC readings. So I take it that the transformer has to be toasted. The rectifier (ITT B80 C3200/2200) shows a resistance of about 16kΩ one way between the AC and the DC terminals and about 46kΩ the other way.
Before I intend to use an auxiliary power supply or replace the transformer with anything, I will of course hunt down all of the unwanted voltages and connections to the ground where there should be none. All good ideas are welcome. :)
Menahem Yachad: 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.
Thanks Menahem, the mains voltage issue is now sorted out (voltage selector switch) and I looked at those you suggested, they both seem to operate ok, the motor gives a static resistance of 21Ω and (unfortunately?) the coil for the dropping tonearm gives a static resistance of 8.6Ω (Ohms, maybe it's better not to use the symbols on web forums, with no UNICODE guarantee across readers).
You say it "should measure a minimum of 9 ohms, now it measures 8.6 ohms, Could that blow a fuse? Or does it just mean the for the near future I would need a) a new coil? b) someone really handy rebuild that coil for me?
I'll need to find Mika then, unless he happens to be the same guy the Classic Audio folks use, in which case I have found him. :)The biggest problem at the moment seems to be the clearly non-functioning transformer. I guess someone can also rebuild those?
TR28 is part of the motor drive circuit – which means that the motor was subjected to severe load, which caused that transistor to heat up and burn the PCB.
So, you MUST look for the cause in the motor area – something prevents the carriage from moving freely to the left or right.
thanks again, ok I will look. Now of course I have the tonearm rolled all the way to the right. It was a bit over half way to the left when it quit. But it had successfully played two and a half LP's that same day, and two 45's without any glitches. Well, perhaps that proves nothing, except that all the automatic functions were working for half a day.
I don't have the schematics here, I can look tomorrow and roll the tonearm all the way to the left to see if there could be any obsctruction or something stopping it. Which is the TR28? How do you think the resistances measured are? And which transistor burned out? I thought the transformer was so far the only thing definitely damaged?
TR28 is the burnt transistor, which is shown in the picture which you sent me.
TR28 indicates where the problem occurred, in the motor circuit, and probably due to a physical obstruction or short in the motor travel.
IF the transformer is damaged, then that was a secondary effect of the stress imposed on the entire electrical circuit.
There are a LOT more parts which need to be replaced on that PCB - your thinking that there are only 1 or 2 parts to be replaced, is completely mistaken.
8.6 ohm is probably OK, based on your multimeter's error.