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This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Finally I have time to start on the BL/BM 5000 Amp and receiver. This is going to be a long thread, I have never worked on these items before, but I want them to come out working and looking as near to original as possible, where I will lean more to function than look if I have to compromise. I will however stray away from the original if better or more reliable components are available, this to get the best working and sounding equipment possible within my means, economical and knowledge. Along the way I will ask some stupid questions, where Martin will answer "we are here to help not to educate radio technicians" , and others will tell me to do some research before asking questions, Normally in my threads I and some others members (no names) stray away from the core and have long discussions about something else, please keep to the matter at hand and if you want to stray away, post a link to another thread. I will welcome all the help, remarks and good advises from all members, if questions are asked I will do my very best to answer them.
In this thread I will concentrate on the BL 5000, the BM 5000 will get a separate thread.
History: I bought the BL/BM privately from an E-bay member on May 4, 2015, and shipped from Wilmington MA to McAllen TX, where it arrived on May 8, 2015. I picked it up there on July 26 and brought it to Mexico city by car (1200 Km.), on the BM there is a sticker attached "Audiokrafters" with 2 addresses, one in Washington DC and one in College Park Maryland a short search didnt come up with info about it, so one wonders how it ended up near Boston MA.
First pic at home in Mexico
Collecting Vintage B&O is not a hobby, its a lifestyle.
This should be fun Søren. You can be sure that everyone will be supporting you on this. In the end you will have a nicely restored, classic system to enjoy.John
The first help already there, Square4 will send to my son in Copenhagen 3 push buttons for the BL and an antenna knob for my Beolit 505, amazing amazing
Square4 is a long time member we hardly ever see on the forum, but he is there watching, THANK YOU.
Jacques
I'm lucky enough to have met both Søren Mexico and Square4 in person and I can honestly say, that bothare true gentlemen in the best meaning of the word.And Søren, knowing your skills and the way you take on new challenges, there's no doubt in my mind thatyou will end up with one of the best and nicest Beolab 5000 systems ever.If there's anything I can do to help, just say the word.Martin
Thank you Martin for the kind words, the Square4 part is totally correct, but about me there are other opinions , but lets get serious.
The number, now this is a US version Series 80, figure that, the Danish versions goes 01 to 09 something, but Frede or Martin will know why.
This one has been checked and found OK by Karl Hansen
To check it I will have to open it, done by loosening 2 and removing 1 screw, red arrows, the outer screws are the 2 inner ones, loosen these only and pull back and up and the top cover comes off.
Well the 3rd screw was missing, some has been, or tried to get, in there
I did see some corrosion here and there on the outside
It didnt stop there the inside is worse, reminds me of the BM 4400 I made (Still my most used and still going strong)
That transformer housing makes me feel bad, I am glad I didnt connect the BL before opening.
Right in the middle of PCB No. 2 there are signs of a spill or something
I will split it up a little, i told you it will be a long thread
Continuing
First PCB open, I like this construction, easy to get at
These blue caps change color when going bad, measurements will show at a later time.
The PCB below is dirty but apart from oxidation on the trimmers no visible failures
The other PCB open, again the color change on bad caps.
Here close up, and that also explains what I thought was something spilled, the yellow one blowing its head off.
And here the "spill" one, leaking all over the place
Even down to the big caps, can this also be the cause of all the corrosion ???
Dirt and corrosion mostly in the transformer side
To open the bottom cover
The leaking cap went all the way down to the bottom cover
The envelope long thought about, and a loose sticker, whereever it came from
And here it is, maybe only touched by one of my girlfriends hands until now, if you want copies just tell me
The front 2 Allen screws off (4 mm Allen key)
When off check for for 2 washers
Off, sliders OK, but yes a little yellow
Missing lettering even on the volume, wonder what hey purred on there
The push button front, pull off all the push buttons and unscrew the 2 supports
Off. For the power lamp there is a diffuser, a simple piece of tape
Dirt and some unknown fibers, wonder where they come from, the missing lettering sucks, I am thinking about metal engraving to solve that
These fibers I find mostly on the outside, I wonder if the BL was stored in a Sisal rope or in a marihuana factory, I somehow recon these fibers
And thats it for today, tomorrow I will have to get at the transformer
Rich:Good luck old friend! Wish I had a tweeter to contribute!
No need for a tweeter, because of you my M70s are doing good work several hours a day, even the BM 4400 at full power they handle without complaining
I am thinking about that transformer since yesterday, I will try to get it out of the housing, and evaluate, I think the most damage is to the top cover, and that is easily made, or if the corrosion damage doesnt go too deep I can paint it or nickel plate it. But later today I will continue dismantling, and then we will see
Have you asked Frede what he does about it?
The way Frede works is incredible, when he finish a piece it looks as good as or better than new, inside and out. He has very good suppliers where he doesnt do it himself, I will not be able to compete with this. He would probably just scrap the box and put in a new one, or one saved and repainted or galvanized from another unit. On the other hand I am hoping to see some comment from Frede later on when it gets critical.
Should you need a replacement transformer made, I can recommend The Toroid Company in the US. Their engineer was very helpful in designing the replacement for my Beogram 4000. Hopefully, the rust is just on the surface. You have to wonder about the environments some of these pieces have been exposed to over the years.How are you planning on redoing the missing lettering and markings on the face of the unit?
sonavor:How are you planning on redoing the missing lettering and markings on the face of the unit?
I will tomorrow go around the corner, there is a company making medal, trophies, cups and things, they also makes fine print memory plates on all kind of metals, I will start there.
Moving on, the transformer comes out easily, 4 screws from the bottom
Then take out the sopport for the PCB and turn the PCB backward
Then desolder the secondary feed leads, sorry bad pic
Take out the cover, Loosen 2 screws holding the fuse board to the sidewall
Desolder 2 wires coming from the voltage selector
Unscrew the voltage selector
And then pull out the transformer with fuse board and voltage selector attached
Looks bad with all the rust, I will clean it all very properly, and then add some resin to the inside off the housing, where possible, just to stop the corrosion there, the outside will be painted.
Following with interest as usual Søren, best of luck and thanks for the brilliant pictures as usual!
Ben
I now had some space for working, but dirt dirt everywhere
I desoldered the wires for the power cord and the wires for secondary power supply and pulled them out
Time to get on with the big caps, loosen these from below
Taking off the cardboard cover you will find a Temp switch, switches off at 65°C, its attached to the cap support with a small nut, I took it off to clean the support
Desoldered from the caps and marked all the wires properly
I then unscrewed all the right side switches and sliders, this from below and the front, I could then get the bottom cover off, and swing out the whole package to get access to the main rectifier, the sliders and the switches
Here one slider, I like this better than the ones from my BC 2000 and my BMs 1900,2400, 4000, 4400. Just pull off the Jesus Christs then pull out the shaft and ready to check and clean
Nearly forgot to show you, the big caps out, and leaking even the biggest one I think
I checked the transformer, first for resistance in the coils, that was OK, then connecting it to my variac, running it up slowly from "0" to 120V, no problems at 120V I got 72V AC, also the rectifier turned out good checking with diode tester, and the fuses was also OK. I take this as a good sign.
I am now considering if I go professional, and desolder the different PCBs, switches and other component from each other and go all out on this one, having it all connected to each other during working and cleaning will result in some broken leads and difficulties cleaning properly, on the other hand desoldering some 200-300 points will with guarantee give other problems, I will rest until tomorrow and then decide.
But recommendations and good advises are Welvome, I feel like between a rock and and a hard place
If you take apart wiring make sure you label the wires really good before you desolder so you can easily find their correct place again. I think I would go ahead and get everything out of the chassis so you can properly clean up and put a stop to the rust. Does the unit smell musty? I am wondering if the previous owner stored it in some basement with that corrosion.That is good news on the transformer. I think you are probably good there. Those sliders look a lot heavier duty than the type used later on. Keep up the good work.
sonavor: If you take apart wiring make sure you label the wires really good before you desolder so you can easily find their correct place again. I think I would go ahead and get everything out of the chassis so you can properly clean up and put a stop to the rust. Does the unit smell musty? I am wondering if the previous owner stored it in some basement with that corrosion.That is good news on the transformer. I think you are probably good there. Those sliders look a lot heavier duty than the type used later on. Keep up the good work.
Yeah, you are right John, I will do it, its the only way to do it correctly, my photo album and my notebook will be overloaded, tedious work but will start that tomorrow if no real jobs comes in.
I am making a time and price calc for this restore, it may be interesting to see how much time an amateur like me put into a job like this.
I was thinking about sending my items to Frede, but the long shipping ways and Mexican customs scared me off. What Frede charge is more than reasonable, we all know the problems you can run into with each unit, and each unit different.
As luck will I have great experience in taking things apart and putting them together the right way again, Getting something in my hands I´ve never seen before brings me joy. My daily job is all routine and ones brain goes idle, thats one off the reasons I choose this hobby, it brings the tired grey cells into rotation again.
Today I will have to make some secure storage space for the components and then I can start taking the BL apart the right way, luckily I see no repair jobs done in this one so I dont have to worry about that. One problem is that I will have to have the BL and the BM apart before end of this month, I can then make an order to Martin and my son can bring it when he comes over in September, my hope is to have both units ready by Xmas.
Do you think all of those leaky capacitors are the source of the corrosion of the chassis?
John
sonavor: Do you think all of those leaky capacitors are the source of the corrosion of the chassis? John
I am almost sure about it, the caps leaks acid and even the fumes will work slowly on all steel/iron surfaces, and here we are not talking about the small caps on the PCBs but the big ones, these are placed directly beside the transformer and the corrosion is only in that side of the unit. Comes to it that the unit may have been stored in an attic or the like. Once corrosion gets started it continues with the help of humidity in the air.
I will clean it off as far as possible and then paint it with "anti rust" primer, 2 layers, then seal it with a special marine grade polyester resin, I used this building a rowing boat for my son some 15 years ago, and the boat is still floating without leaks
Doing it the hard way, here is what I got out today
Its tedious work, I select the wires I want to desolder, I then take a pic or 2, upload them to the computer, and then resize or crop them and then add the wire marking like this
Here a overview from the middle of today I will continue tomorrow and then I can begin cleaning
That's what I call an integrated amplifier, far from the Japanese ones that were full of air.
chartz: That's what I call an integrated amplifier, far from the Japanese ones that were full of air.
Nice to work on though, wiring easy to follow with the marks on the boards, even so I have made until now about 200 pics, many off these like this
Today I got it all taken apart, and did some measurements on the output and power transistors, found 2 bad 2n3055, one in the power supply and one in one of the channels, didnt follow up on witch channel, but will need at least 3, 2 for the channels and 1 for the power supply. I also checked a pair of the trimmer resistors, there are some very big ones in there, they all seam to be OK, but the smaller sizes erratic. Those big trimmer resistors I have never seen before. Here the result of todays work
Here the mechanical part, all ready to clean, paint and what ever, but before cleaning I will have to open the BM 5000, if parts are needed I will have to order from Martin so he can send to my son, and the son bring them in September
Great thread Soren. You have a good note system which is critical with not just the amount of work you have but having to wait so long for your parts.
Keep up the good work.
chartz:Søren, your pictures are too compressed, we can't really see what you did! You can post 1500 or 2000 pixels when needed. Three 3055 belly-up, and the seller claimed it worked. Did you evaluate him at all? What a nice thread.
Three 3055 belly-up, and the seller claimed it worked. Did you evaluate him at all?
What a nice thread.
I will post more detailed when I start repairing and assembling, The seller only claimed the the power light came on, and the usual excuse, no speakers or other things at hand to check further. Here the result of the TR check, checked with diode test.
Here a detail about the output TRs, on the B and E leg there is a coil attached, probably to hold the fiber disk in place, and a soldering help for the connected wires.
The TRs for right and left channel has a plastic coated nut attached to the lower screw, these plastic covers break easily when trying to loosen the nut, (old brittle plastic symptom). There are 4 nuts, I broke 3 of them
Here the cooling ribs without TRs
And here the TRs out and tested, the "B" means BAD