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
And after.....
I'll try and bring it down soon - I'll make sure it is working first!!
Peter
finished with the carriage switch assemblies and need to set them up as per the service manual, something looks a little odd with the measurements shown against switch activation points.....but will need to give it a little more thought, meanwhile fitted a new voltage regulator off board in accordance with Martins advice.
Having a clear out here - would you like a pair of Beovox 5000s - they are the correct speaker for your Beolab 5000 - they match well. Teak and legs all present and correct - were repaired professionally some time ago but not used except as a table since! Not that small....
Will accept a look at my BM8000 as payment!!
Sounds like a deal to me Peter ;¬)
I'll have to work out when I can get down - will be a weekend as working flat out at present!
Martins mod complete im back to this......on startup the platter runs at 45rpm, 45rpm lamp glows and the platter moves towards the centre, the logic looks like this which seems fine to me..
However when I press the 33rpm switch the logic flips over fine, the platter runs at 33rpm, the 33rpm lamp glows...the logic looks just as I would expect
And thats great...what I dont understand is when i release the 33rpm switch the whole thing flips back to 45rpm.....surely this shouldnt happen as it must latch? I have tried replacing the chip to no avail......am i missing a trick here?
Perhaps there is a pulse on one of the NAND gate inputs that is flipping the latch back.
-sonavor
Shorted 45 contact on the frontpanel?
Martin
Just for the hell of it I have had a look inside these NAND gates, I always thought that the outputs from these chips where driven from there own internal 6vdc supply but I didn't realise they also provide the voltage at the inputs too. So having sorted that out I can see the required configuration for 45rpm operation.....the yellow highlight represents a high state or something above 0,5v
Operating the 33rpm switch drags down the high input which flips the gate over to drive the 33rpm lamp and motor speed.....
All that said it looks to me like inputs 2 & 9 provide the latching when the gate flips over......I'm not getting this latching
Pondering this in the shower this morning, when selecting 33rpm the 45rpm output from the logic gate goes low which de energises the speed control relay, I hear it click out and the speed changes to 33rpm....the output from the logic when 33rpm is selected only switches the 33rpm indicator lamp on via 1TR1 and runs to ground via resistor 1R2.....i'm now suspecting insufficiand load on this output? will check the resistor out this evening
Peter,
Frede doesn't have any of those trim pieces anymore. I JUST asked him. I "may" have a new source, but I need to see the product before commenting. The trim piece on my Beogram 4000 is adhesive tape, and now looking something less than pristine. I ordered a new trim piece and it is being manufactured, as I type this.
Your advice, as always is spot-on vis-a-vis cleaning a stylus. You guys got me to use the Magic Eraser on my "collection" and it works. However I prefer, when needed, to use alcohol with an artist paint brush.
Much as been said about how these B&O cartridges age, and of course they do. The dreaded flat spots and the hardened suspensions.
I really don't know what makes one cartridge fail/wear-out, and another continue. However, offered only as a hopeful comment, my BEST cartridge is a MMC20CL that is 43 years old. And my daily use cartridge a MMC6000 sounds almost as good.
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
Still working away at this......I have discovered that when switching on the 6vdc drops to around 4.6vdc, smoothing capacitor may be responsible for this, I'm of the opinion that the logic gates are working as designed but I'm still chasing the latching at 33rpm issue.
Did you replace the regulator transistor 2TR6 or just move it away from the board? if you just moved it, I suggest you replace it (BC141).Also check the zener 2D4.And rectifier 2D5 is known to become weak.
To me it still sounds as if the 33 button is held constantly, only interrupted when - and as long as - 45 is pressed.Have you checked the signal from the 33 button?
Yes I did replace 2TR6 with a new device, BC119 however not BC141. I have a new zener for 2D4 and I also have a couple of 2000uf caps I can use to replace the existing dodgy looking pair. I will see if I have a rectifier too when I get home this evening. As for the 33 switch I'm thinking its fine...bear in mind the machine is starting up at 45rpm with the corresponding lamp illuminating and not as it should in 33rpm mode, operating the 33 switch flips the 45rpm lamp off and the 33rpm lamp illuminates.....the turntable drive motor drops to 33rpm too, however releasing the 33rpm switch flips everything back to 45rpm mode....I can see from the circuit that the 33 switch actually de energises the reed relay 2MS2 by diverting its coil voltage to ground and thus drawing the logic input 33' to ground to (via 4D3) which is responsible for flipping from 45 to 33....so everything seems to be working as it I think it should, but it just isnt ;¬)
All the mechanical switches are working fine too.....so I'm hoping re establishing 6vdc across the board will improve things.......
Craig
I meant the 45 switch...I'm getting old.
Tell me about it........
Dave
Thanks for that, the guy has been in touch actually.....and when I get this sorted I will look to the cosmetic side and definitely be in touch with him ;¬)
In the meanwhile I discovered I don't have a bridge rectifier or any 2000uf 15v caps so they are now on order....this evening I decided to remove the 2000uf caps ready for the replacements and discovered this lurking underneath......
Measured up the nasty looking one and found it woefully short of the mark at a mere 20uf...……..
It's buddy didn't fair much better either coming in at
It's buddy didn't fair much better either coming in at 125uf
just as a check on my meter, it wasn't the most expensive piece available, I measured up a new 4700uf cap....
I'm hoping replacing these little fellows along with a new bridge rectifier, and I have already replaced the 6.8v Zener, will go a long way to resolving my 6vdc power rail issue
Received these two today so set too installing them with great expectations.....modified the clamps a little to accommodate them.....
Made sure everything was well insulated, still got everything pulled apart, and powered up.....and finally after what has seemed an age of frustration, compounded by incomprehension, I am rewarded by a start up on 33rpm....with the speed change over manually to 45rpm operating just as it should! this feels like a major victory to me...I was beginning to despair over the stubborn refusal of the control logic to perform despite everything appearing as it should......glass of wine is the order of the evening, will progress over the weekend, for now I'm going to enjoy a rare moment of smug satisfaction ;¬)
Enjoy
Collecting Vintage B&O is not a hobby, its a lifestyle.
Well done, well done!
Jacques
I have one of these in route from the UK as I type. Any questions, please ask.
Craig:.glass of wine is the order of the evening, will progress over the weekend, for now I'm going to enjoy a rare moment of smug satisfaction ;¬)
Had I achieved what you did, after all that, I venture to say it would have been a bottle of wine, as opposed to the more restrained glass of wine. Salute!
Replaced the remaining big caps, I've held them in place with a spot of epoxy until I can come up with something more permanent......
I would use hot glue (i.e. hot glue gun). The glue dries immediately but can be pried off in the future the next time that capacitors need replacing.
Or better yet, get the reservoir capacitor kit from Beolover.
Beolover kit is a true beauty.
Hot glue and adhesive felts (the ones you put under the chairs legs) will do the trick to keep the original brackets with smaller caps. I did this way, and the result is not that bad.
Never thought of using a hot glue gun, will give it a go. Meanwhile I have a new reed relay on order so set about removing the failed component...the 24vdc relat in question is second from the bottom
Un soldered the two red leads and removed as much of the surplus solder as I could from the right hand connection tab, with a little heat to melt the remaining solder I was able to bend the right side tab back away from the reed relay connector thus freeing one side..un soldering the left tab allowed me to draw the switch out from the coil...….
However the patient didn't survive the procedure! so it's just as well it was kaput because it was never going back.....I'm expecting the installation of the new one will be more straight forward