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
Continuing my quest to get some Bang & Olufsen systems from my backlog into service, I started working on some Beosystem 5000 components this weekend. In another recent thread I got my Beosystem 5500 system working again. I did put my Beogram 5000 in that system though as I don't have a Beogram 5500 yet. I haven't decided if I want a Beogram 5500 because I have way too many turntables as it is. I may just build up this 5000 system without a turntable.I also already have a working CD50 unit so I just need to get my Beocord 5000 and Beomaster 5000 units restored.Starting with the Beocord 5000, I discovered its problem is pretty much just deteriorated belts and dirt. The belts are all melted the same way I have found several Beocord 8004 and 9000 decks. The reason I think is improper storage by owners that put these fine machines away. My pictures start with the Beocord already opened up. You can see how to disassemble this cassette deck in Søren's thread.
Here is a closer shot of the top side belt residue.
The belts on the underside were also melting.
There was more belt residue under the big flywheel.
I use cotton swabs and Kimwipes with isopropyl alcohol to clean up the belt residue. It has to all be cleaned off because it is like sticky tar. You wouldn't want any possibility of that stuff getting on a tape.
Once everything was clean I put new lower belts on. I got this belt kit from Martin quite a while back intending to use it way before now...but time goes by fast.
Here is the new topside belt.
While I had the cassette deck opened up I cleaned off all dust and dirt that had built up and I installed a new drawer belt.
The next step was to re-assemble the Beocord to try it out with the new belts. It played great. I tried several cassettes over a couple of hours and they all played as I expected them to. I am not going to mess with any recapping of the Beocord at this point. I might revisit that later if other problems come up. However, I do have another Beocord 5000 of this same type I will be wanting to fix at some point. When I finish recapping the Beomaster 5000 I will test out recording from the CD50 to this Beocord. For now though, I am putting the cover back on.
Good job on the cleaning, I was lucky not much cleaning to do, and the belt tracks looks OK to me, everybody else have these belt residues I never had a unit with "melted belts"
Collecting Vintage B&O is not a hobby, its a lifestyle.
Moving on to the Beomaster 5000 (Type 232x).Here is the Beomaster with the cover off before starting work on it. It is very similar to the Beomaster 5500. A nice feature of the BM5000 is that it has a swing out control panel that allows some basic functions to be operated without a remote control.
The top board (tuner section) swings away to open up access to the inner circuitry like the Beomaster 5500. The BM5000 also has the cooling fan and semi-clear plastic air duct that also secures the large power caps.
It is necessary to pull out the two large capacitors and the air duct to fully remove the power board.
Like the Beomaster 5500, this Beomaster is quite easy to get to all the parts. Here is the chassis with everything removed for work.
Too many threads to follow!!! Good luck, John.
Here are all the components laid out and ready for the recap. There are a good number of electrolytic capacitors to replace but I think I have all of the replacements in stock. I just need to warm up my de-soldering gun and get to work. I hope I can get everything done in a couple of days as I have a bunch of capacitors coming in for my Beogram 8002 projects this week.
My Beosystem was like yours, I bought it some 3 years ago, all I ever did was cleaning and change the belts, and in the CD50 I had to dismantle the motor and clean out and sand the bushings a bit, Since then it has been working like a charm, the BC is top notch I recorded some 12 tapes with my old 45s and it plays them without any problems, I even got some original B&O tapes from 9Lee NOS,and I consider the BG my best TT playing with an MMC2 from Axel
Søren Mexico: My Beosystem was like yours, I bought it some 3 years ago, all I ever did was cleaning and change the belts, and in the CD50 I had to dismantle the motor and clean out and sand the bushings a bit, Since then it has been working like a charm, the BC is top notch I recorded some 12 tapes with my old 45s and it plays them without any problems, I even got some original B&O tapes from 9Lee NOS,and I consider the BG my best TT playing with an MMC2 from Axel
I have really been enjoying my Beosystem 5500 lately and expect this 5000 system to be just as nice. I feel bad now that I took so long to get to these. But better late than never.
Rich: Too many threads to follow!!! Good luck, John.
Thanks Rich. Yes, this must be the season for restorations. It is good when the workbench has a lot going on.John
I may be wrong but I dont remember seeing a Roederstein cap in any of my components, back in time I asked Martin for a kit for the BM 5000 but he didnt have it then, maybe he has it now
Last night I got the output amplifier and power board recapped with capacitors I had in stock (from the Beomaster 5500 restoration). That included the two 10,000uF capacitors (C6 & C7). The Beomaster 5000 service manual has a typo and lists them as 1,000uF capacitors. The recap went smoothly and there were no surprises (so far).
I started on the preamp board next and discovered one of the RCA input jacks is missing and another one is broken. Fortunately I have a spares Beomaster to steal parts from. The spares unit is an incomplete Beomaster 5000 I bought from someone that gave up a repair on.
This is the preamp board of the Beomaster 5000 I am restoring ready to have the RCA jacks re-soldered. There are a few traces on the PCB that will need repairing in the process. The spare BM5000 had more faulty PCB pads so this is the one I am going with. I will recap the board and solder the RCA jacks back in place tomorrow.
The preamp board is now recapped and all but two of the RCA jacks are back in place.
Tomorrow I should be able to repair the two broken pads and traces for the last two RCA jacks. That will put me at the halfway point of the restoration. I want to finish and be using this system by the weekend.
The preamp board had quite a few 22uF, 16V bipolar caps. I replaced them with some Nichicon Muse BP capacitors that I had in stock. There were eight 10uF, 16V caps in the signal paths of the preamp board so I also replaced those (polarized caps) with some 10uF Muse bipolar caps. Same for the two 2.2uF caps on the phono inputs. Those were replaced with 2.2uF Muse bipolar caps. I did a similar replacement on my Beomaster 5500 and am pleased with that result so this should work really well and I had plenty of the capacitors on hand.
The preamp board broken pads are now fixed and the board components are all back in place.
I didn't replace the two electrolytic caps (470uF & 68uF) on the blower fan board. I didn't have a 470uF, 50V cap in stock and both capacitors measured good. That being the case, I re-installed the output amplifier/power board and the preamp board into the bays of the Beomaster chassis.That puts this project at the halfway point. I should be able to finish this in a couple more days.
Tonight I got the IR board (board 9) recapped.
Then I moved on the processor board. I finally ran into my first hurdle. I hadn't checked the manual but this Beomaster 5000 doesn't have a coin type lithium battery like the Beomaster 5500 had. It has the barrel, CR1/N 3V lithium battery. I have a few of those but not with PCB mounting tabs. I have some board mount holders for that type of battery but there isn't enough room in the processor board case. That means I'll have to order a board mount CR1/N battery and they are kind of expensive...especially shipping. Surprisingly Mouser doesn't carry them either so I can't run over and pick some up tomorrow. It looks like I won't be able to complete this project this weekend as the battery won't arrive until next week.
I went ahead and removed the old battery. I cut the leads to remove it before de-soldering the mounting tabs. That is because I don't like explosions and these old batteries can do that. It's better to be safe than sorry.
I noticed that inductor L9 looked kind of melted so I pulled it out to check it. It measures okay so I guess it is fine.
I replaced the electrolytic capacitors. For the 220uF, 16V, all I had available in an axial type capacitor was a 220uF, 50V Nichicon so I went ahead and used that for now. I have an order of parts about ready to submit to Mouser soon so I will add some 220uF, 16V or 25V axial capacitors. If I get that order before the battery arrives I'll change out my 220uF, 50V cap.
My spare Beomaster 5000 processor board appears to have a good battery still so I recapped that module and used it in my project until my 3V lithium battery order arrives (next week).
Before I started this unit had a problem with the control panel door opening up as soon as power is applied. I decided to see where things stand now after recapping the power supply, preamp and IR control boards. The panel door problem is still an issue. The control to the solenoid that operates the door latch goes through connector P15 on the preamp board. Measuring the signal on that connector I see +12VDC on P15-2 and +0.5VDC on P15-1. The P15-1 signal appears to be controlled by the "Open" signal from IC5 (MM 5450) on the preamp board. I am not seeing how the front panel door button is controlling that signal though. When the Beomaster is plugged into AC power it immediately unlatches the door.
Here is are the measurement probes on P15-1 to ground on the preamp board.
I tried the spare Beomaster 5000 preamp board but it has the opposite problem. It doesn't have any power on the relay or the IC. I might try recapping that board and seeing if that changes anything.
sonavor:Before I started this unit had a problem with the control panel door opening up as soon as power is applied
I have the opposite problem, my control panel wont open when pressing "open"
sonavor:The P15-1 signal appears to be controlled by the "Open" signal from IC5 (MM 5450) on the preamp board. I am not seeing how the front panel door button is controlling that signal though.
Through software.
--mika
tournedos: sonavor:The P15-1 signal appears to be controlled by the "Open" signal from IC5 (MM 5450) on the preamp board. I am not seeing how the front panel door button is controlling that signal though. Through software.