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
Dom
2x BeoSystem 3, BeoSystem 5000, BeoSystem 6500, 2x BeoMaster 7000, 2 pair of BeoLab Penta mk2, AV 7000, Beolab 4000, BeoSound 4000, Playmaker, BeoLab 2500, S-45, S-45.2, RL-140, CX-50, C-75, 3x CX-100, 3x MCL2 link rooms, 3x Beolab 2000, M3, P2, Earset, A8 earphones, A3, 2x 4001 relay, H3, H3 ANC, H6, 2014 Audi S5 with B&O sound, and ambio
Welcome back Søren!
Peter is quite correct we were just keeping it going and in doing so I learned a few interesting things, so I, like everyone else are ready for your steady stream of BM 4400 reports.
Wishing you all the BEST of luck!
Jeff
Beogram 4000, Beogram 4002, Beogram 4004, Beogram 8000, Beogram 8002, Beogram 1602. Beogram 4500 CD player, B&O CDX player, Beocord 4500, Beocord 5000 T4716, Beocord 5000 T4716, 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
Søren Mexico: It has been interesting to see how wide a thread can go, the latest, interesting about power in 4500 9000 BMs, a time long it was a chat thread for Jeff, me and some more, I enjoyed all of it.
It has been interesting to see how wide a thread can go, the latest, interesting about power in 4500 9000 BMs, a time long it was a chat thread for Jeff, me and some more, I enjoyed all of it.
Yes - it's amazing here on Beoworld...You'll never know where the threads will end up. Sometimes you might forget where it started...Well - I'm looking forward to the continuation
Hi Steffen,
Yes it is remarkable how these threads morph.
During Søren’s interlude I learned a GREAT deal about BeoCenters in general and the 1900 Beomaster series in particular. If I had any more unresolved questions I would have started another thread so not to interfere with what is going to be an exciting step-by-step process on Søren’s Beomaster 4400.
I don’t think there have been too many other threads as interesting as this one has been with the superb photos of the transformation.
The meticulous work on the aluminum fascia, the hand-made replacement slider, and the restoration of the veneer all speak volumes about the care and skill Søren is applying to this project.
Truly this has been a labor of love!
I believe that we all held our collective breaths as Søren worked on the electronics and ached when his best efforts failed to resolve the various problems. (I know I did anyway!)
Now with Martin’s kits in hand we are ready for VICTORY!
Sorry for the delay, as the FS invited friends I had to do my social duties, and cook a meal for all of us, but today I got started.
First of all I opened the BM and took a long look at it, then found the parts from Martin, as always from Martin with an instruction, but this one is NOT for beginners, some pre knowledge is essential. I will have to use the web to determine, and to be sure of, the pin outs for the transistors, and refresh my memory for cathode and anode on the diodes.
I opened one of the kits from Martin, and sorted out the Resistors, then took a look at the power transistors, In my unit I had TIP 141/146, Martin provided TIP 142/147, well Bigger is better. Here the Resistors sorted by size
Took out the PCBs 3 and 4, the PCB 2 I lifted out and bend aside over the tuner, then gave it a long thinker again, take out the main PCB or just try to do the work with the main PCB attached, started desoldering the power transistors while still thinking.
I decided to free the main board, but leaving the wires going to front switch board, I would then be able to kip it up and work from both sides with out moving it too much. Desoldered the wires running in the cable channel, then desoldered wires from the fuse holders and cut the other wires at fuse hight, this to save the copper shield glued to the channel. I could then take the channel out with the wires inside, then get the big cap holder out without desoldering all the wires going to and from the caps.
Then desoldered the main fuse holder and the heavy wires.
Then desoldered the 6 wires going to switch board, (only 4 shown in the pic.)
After loosening the clips, I could then kip the board up and have access to solder and component sides.
I then desoldered R 180,181,182 and a small capacitor, just to try how much heat was needed, and best way to do it, I choose to cut off the component from the pegs, then its easier to desolder the pegs, using first the pump, and then just push them out to the component side, taking care not to loose them, I dont want these floating around in there when I finish. And thats it for today, it may take some time before I get back to it, as I have some jobs coming up outside Mex. city. Long way to go
Collecting Vintage B&O is not a hobby, its a lifestyle.
Now we are back on track.
Søren, my friend, you have my upmost respect to tackling such an intimidating project, but clearly you know what you are doing.
The photos were most helpful in showing what you are doing.
A project like yours can NOT be rushed, but as it unfolds, you know we are all interested. When you are done, you will have a magnificent amplifier, one you can appropriately point to with great pride.
Wow Søren, I'm impressed!
Never would I have had the guts to take the main board out!
Bravo, and by all means keep posting wonderful piccies!
Jacques
Will try to continue tomorrow Tuesday, I have question.
Does anyone have a better repair manual than the one from the forum site, the schematics are useable, but I would like to have a better copy from the solder side component placement charts at the moment I´m working with this one and as you see its not the best, so if someone has a better copy please mail me.
Have you checked Beophile and *** removed ***?
chartz: Have you checked Beophile and *** removed ***?
I did Jacques, same manual as "ours", but John, (Sonavor) will scan and send me a copy, he apparently has an original, Thanks John
Got the color print from John this morning, there are some differences between the print and my BM, so I'm going even slower now, checking every single component, and making a list of values for all components, will continue later tonight and bring a first report with pics today or tomorrow morning. I still have problems with the cleaning, you may remember how dirty this one was when I got it.
Hello Søren,
You are going about it absolutely right, when unsure, go slow and TAKE YOUR TIME, as your Beomaster 4400 isn’t going anywhere.
This is going to take some time, but when your 4400 is done I am really looking forward to comparing notes vis-à-vis how yours performs as compared to mine.
In truth it will be a little like comparing apples to oranges, but maybe we can make a bit of “fruit punch.”
Found some differences between the print from John and my schematic and my PCB 5, R 166 is 22 Ohm (John), and in my sch. and on the PCB 46 Ohm, and R 156, Johns is 56 Ohms and mine is 33, so I carefully check the components, after desoldering, and then the new components before attaching them. Until now I found no bad components. Took out a couple of transistors today, will check them against the new ones tomorrow. The kit that Martin provided seams nearly perfect.
Found one more failure, I took off the P11 plug a couple of times in the past, it may come from that, but who knows, I may have missed it checking.
Here from the component side, still strugling with the cleaning, I want that PCB to look like in the upper left corner, there I applied a tiny drop of fine oil, spread it out and dried it of with a pipe cleaner.
Here the solder side, still with some leads to cut.
I'm slowly getting the hang of it now, I hope to be able to do more tomorrow.
Søren Mexico: Found some differences between the print from John and my schematic and my PCB 5, R 166 is 22 Ohm (John), and in my sch. and on the PCB 46 Ohm, and R 156, Johns is 56 Ohms and mine is 33, so I carefully check the components, after desoldering, and then the new components before attaching them.
Found some differences between the print from John and my schematic and my PCB 5, R 166 is 22 Ohm (John), and in my sch. and on the PCB 46 Ohm, and R 156, Johns is 56 Ohms and mine is 33, so I carefully check the components, after desoldering, and then the new components before attaching them.
Søren, I think you will need to go by the Beomaster 4400 Service Manual parts list and compare to your actual PCB. The nice color PCB layout in the service manual either had component value changes that weren't kept up to date or there are typos. In the same service manual that the PCB diagram came from - PCB 5 - R166 is listed as 47 Ohms, 5%, 1/8 W resistor in the parts list. So the PCB diagram has the wrong value. Hopefully though, the traces on the diagram and reference designators are correct. The schematic diagram of the service manual also has 47 Ohms as the value for R166 (PCB 5).
For the other resistor you questioned, R156 - the parts list has that as 33 Ohms, 5%, 1/8 W. The schematic does too.
Hope that helps,-sonavor
Thanks John, with the kit from Martin came a list of all components, until now the list is identical to my PCB 5 and the schematics from the manual.
The PCB color print has some small differences in the traces, but the component placement is same until now.
Ran into the difference between the manual schematics and the solder side print. To know where I was and to remember placement of the components I made a print from the left amplifier section, glued it to a piece of soft insulation board, I could then just press the components in place.
But suddenly I had a 10K resistor with no place to go. came from somewhere in the red ring
So I went looking in the schematics, and yes there it was, but easy to miss, R 188, siting in an area where the Resistors has lower numbers, and the schematics typically hardly readable in that area.
R188 is inserted in series with C140, between TR116 Emitter and TR113 Base
At first I thought the coil L100 was bad soldered, but it was a hole in the PCB where the leads from R 188 and C 140 was united, clearly a modification from the factory.
I hope my print glued to the board will help me and my bad memory again, I'm having fun here
What if the bad solder you had missed was the original problem?
Good job mate, keep it up!
chartz: What if the bad solder you had missed was the original problem? Good job mate, keep it up!
If I dont find anything else it may have been that, but as I had problems in both channels I dont think the bad solder is the only problem, there must be more somewhere.
Small problem, I cant get a 3n3 capacitor on the fast here, can I use a 2n2 or 4n7
Søren Mexico: Small problem, I cant get a 3n3 capacitor on the fast here, can I use a 2n2 or 4n7
Depends totally on what that particular cap is doing in the circuit.
You can always try 2n2 and 1n0 in parallel.
--mika
It is the C133 cap, 3n3, parallel to R154, both going to Base of TR112, just below the red ring
The service manual explicitly says "10%" so I wouldn't want to err more than that. The tolerance is usually omitted in positions where it doesn't matter much.
Thanks Mika, will use 2.2 and 1.0,
Søren Mexico:I made a print from the left amplifier section, glued it to a piece of soft insulation board, I could then just press the components in place.
Like your work plan Soren- very tidy.
valve1: Søren Mexico:I made a print from the left amplifier section, glued it to a piece of soft insulation board, I could then just press the components in place. Like your work plan Soren- very tidy.
Confidence is good, control is better
Søren Mexico: Confidence is good, control is better
No ornery gringo ! :-)
The Mexican way is, fast and unreliable, in the end God will help us
Sick with the pragmatic Danish way as it is faster to do it right the FIRST time!
Piaf: Sick with the pragmatic Danish way as it is faster to do it right the FIRST time! Jeff
+1 Amigo !
Ran into too much job, so no time for the most important, but today I could finish the left channel, I found only one Resistor out of spec will inform about that later. I got the original Repair manual from the bay, and there are some small differences to the on site and to my BM 4400, I make notes as I go and will make a list when finished.
Here component side, got it more clean now
Here solder side
In the manual I bought on the bay, I found some service info/bulletins
Peter if you want them as PDF to the manuals, PM me
I will change the R 180 to 220, it may be one of my problems.
As I'm changing all of them, no problem, and the matching TRs should be no problem today, I read something about that, and today's production is more precise than 30 years ago.
This one is from November 1978, so it is more frequent in the early production numbers
Very interesting. Thanks for sharing!
I'm not sure Martin's output transistors are paired. Are they, Martin?
If you read this Peter, you never published the Beomaster 8000 information book I sent you!
chartz: I'm not sure Martin's output transistors are paired. Are they, Martin?
In kits, where needed, yes.
Søren got a prototype kit that was meant for my own use only but still I believe theyare paired within a 2x100 pcs lot from the same production batch.Nothing to worry about, anyways. The Beomaster 4400 is not the worst when it comesto exact HFe matching. The totempole-ish series coupling of the output ICs andthe emitter resistors, even if fairly small, will still compensate for a good amount of HFe skew.
Martin
Got all components out from the right channel, tomorrow I will check them all against specs, then on to make a report of the component check for both channels. and start on finishing the right channel, I hope I can start assembling the BM in the weekend, if that goes well, maybe a first test.
Today I found some muscles I did not know that I have, upper back, neck and shoulders hurting, this is hard work folks.
Hey Søren,
I gotta tell ya, you don’t look remotely like your Avatar, which more closely resembles the Frito Bandito.
As for the work, hard work it is indeed. Fortunately you enjoy this labour of love. (I for one find soldering components amazingly stressful.)
In any case you are getting close and that is more than exciting. I have all my fingers crossed for you! ¡Buena suerte!
Piaf: Hey Søren, I gotta tell ya, you don’t look remotely like your Avatar, which more closely resembles the Frito Bandito. As for the work, hard work it is indeed. Fortunately you enjoy this labour of love. (I for one find soldering components amazingly stressful.) In any case you are getting close and that is more than exciting. I have all my fingers crossed for you! ¡Buena suerte! Jeff
Frito Bandito, My avatar is a typical Mexican caballero, Actually I enjoy soldering, more so with my new soldering station, I'm getting worried though, I didn't find any serious failures in the left channel components, one resistor way of, and that was it, transistors, caps and diodes all measures OK.
I was waiting for you to cheer me up, and there you are, thank you. I got the pull back reading Sonavors excellent thread about the BG 8002 and then Rich gave me an early birthday gift, a Beocord 5000, type 4716, this forum is just amazing.
Hi Søren,
I am so glad I cheered you up! You do amazing work and are an inspiration to us all….. and I mean that with all my heart!
So when is your birthday? Whenever it is, I wish you a very happy birthday!
I just have to ask you, did you understand my reference to the Frito Bandito?
The Frito Bandito was a character from the Frito-Lay Company in the late sixties, and as such close to my heart.
All the best with your 4400.
And when you have the time after you have succeeded in conquering your 4400, I really would love your input on mine.
Søren Mexico: I got the pull back reading Sonavors excellent thread about the BG 8002
I got the pull back reading Sonavors excellent thread about the BG 8002
Me, too. It's John's fault - I needed a new project so I bought these P30s. Going to hang them on the wall in the garage with Beosystem 1900 and put the S40s in my daughters' room.
Continued good luck with the BM4400.
Rich: I bought these P30s
Good price, got P45s love them, hang them on a good solid wall
Measured all components that I took out from the right channel, only failures I found until now is:
Bad solder on P11 pin 1, which is the +35V feed for left channel, but the 35V was there on the board.
R164 shows 2K750, should be 2K2, R264 shows 2K570 should be 2K2
Then I found this, all the old TIP 146 shows like this + -, and the new TIP 147 (measured 2 of them). But all 4 ?? Am I missing something here ??