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
Greetings all,
Well, where should I start ?
Thought I got a good deal on a Beogram 4000 in VG with arm-lowering problem and loose on-off switch.......that was the seller's description of the table - what a joke !!!
Why sellers need to be so dishonest when infact they only offer junk I will never understand!
those 2 minor problems I fixed very quickly and the arm lowers nicely as it should and that on-off switch is back in position but.........
Turn on the table, the arm moves in position, lowers on to the record and suddenly a kind of
'slow' fast-forward engages and drags the arm-stylus across the record ????
I can slow-down that problem by playing with that trim-pot next to the slider motor - see pic
But can never get the spindle to the normal tracking motion consistantly ??
It starts off ok in normal tracking motion but suddenly rotates like in a 'slow fast forward' mode.
I am totally in the dark what could-is the problem here ??
Would someone be in a position to offer assistence ??
Thank you so much - ALF
Please click on the link to see the full picture
Thanks ALF
Sounds like a problem with the tracking adjustment.It's the lamp/opto assy at the foot of the carriage, mentioned in the service manual.It could also be an electronic fault but the adjustment is often seen as the sole cause.
Martin
Dillen: Sounds like a problem with the tracking adjustment.It's the lamp/opto assy at the foot of the carriage, mentioned in the service manual.It could also be an electronic fault but the adjustment is often seen as the sole cause.
Yes, and the adjustment could have been ruined during transport.
Jacques
Thank you to martin and jacques for your replies.
Well, as I understand it there is a 100 Ohm trim-pot that is connected to the opto-sensor where you dim the light for that opto-sensor ??
Looking at the incremental rotation of the slider-motor that follows the movement of the arm it seems to come on too often causing the stylus to get dragged over the record.
The brighter the light in the opto-sensor assembly is the faster it drags the stylus accross.
I find it dificult to decribe that in a better or shall I say clearer way. I am not concerned about the slow or fast forward-return function and its adjustment for now or is this connected ??
I was going to install a 200 Ohm trim-pot to see whether that might help ?? The service manual only talks about the FO and FR adjustment.......or did I miss the important bit for my problem ??
Please bear with me as I am not anywhere your knowledge nor experience.......help is still required :-):-):-):-)
The sos is out there - cheers, ALF
Alf, let that trimmer well alone. On my deck, it is on its end-stop, so that the light is the brightest. Frankly, I tested various settings and couldn't find any differences.
First of all, check your stylus.
Then, if the carriage motor works by fits and starts (not smoothly) then the belt is too tight.
Have you read the manual thoroughly? Especially the fault-finding pages?
Sounds like you need to adjust the diaphragm, probably not by very much... leave the pots alone!!! see section 4,6 in the service manual.... I had a similar problem with my Beogram 6006.
Lee
Thanks Jacques fofor getting back to me.....
The stylus is next to perfect, I had records running the whole side without a hick-up. Which makes it even harder to understand the problem !?
As said earlier, the brighter the light is set via that trimmer the faster the carriage-motor spins with the arm lowered !!!!
It is at its slowest with the darkest light-setting which gave me the idea to change that trimmer.
As for the belt, I could change that easily. Naturally I looked at the fault-finding flow-charts but understanding them is another matter for a novice like myself.
Do you have aparticular page or passage in mind from the service manual ? I would be too happy to follow that up or is there a designated trimmer where the carriage-motor-setting can-should be adjusted ?
I don't mean the FO or FR trimmers.
I am sorry if these questions sound funny but it is a steep learning curve for me while your experience and expertise is far in front
Cheers, ALF
Hi lee,
Thanks for trying to help - much appreciated:-)
Do you refer to the suspension-adjustment ??
Thanks again Lee,
I found the section in the SM and shall get on to it right away - will report back :-)
Cheers ALF
Hi jacques,
well, the rotation of the carriage-motor definitely changes with the pick-up arm lowered the brighter the light the faster it rotates ! Why, I am not exactly sure.
Under section 4.6 in the SM as described I tried to adjust the diaphragm to achieve that 1mm spacing.........and showed a lot of patience :-) with the result the carriage-motor now spins in the opposite direction :-((
At best I can get it to not spin at all with the arm lowered. Why am I not amused ??
looking up the fault-finding flow-chart in the SM under 'servo not working' #9........
check voltage 0R3-0R4=24V,meaning both Rs should have 24V, correct ?
Then various actions like adj-repair or replace? Switch........which one ????
Adjust shutter ????? Repair-replace 01L1 ?? Where is it ?
Sadly that all is a bit hard to digest for me
Somehow the android OS has problems with texting......and seems not fully compatible?
Anyhow, the point I tried to make is simply that I amust a tick stressed with that complex machine and questions still remain :-( about ' what next ? '
ALF: well, the rotation of the carriage-motor definitely changes with the pick-up arm lowered the brighter the light the faster it rotates ! Why, I am not exactly sure.
Don't touch anything!
Yes well, clearly the shutter is misaligned. The - challenging - procedure is indeed explained section 4-6, and I'm afraid that your interrogations show that being an absolute beginner, you will have to think hard and watch a lot to do it on your own!
Perhaps what the manual doesn't clearly say is that the shutter must be really well-centered before attempting any adjustment (while screw A is loosened).
Are you 100% certain that your stylus in good (without missing tip) and that enough tracking force is applied?
Hello Jacques,
Thank you for taking the time to help.......yes, in the eyes of experts like yourself I am a beginner :-) but I am learning.
Yes, I can defiitely see the stylus tip - I have had that cartridge in use before without any issues. I will check to tracking force again but it will only show the same: 1.15, checked with shure tracking-force scale, as I do not fully trust the dial on the arm !!
Correct me if I am wrong: with 'shutter' you refer to the metal-tongue which height can be adjusted via shifting the diaphragm up or down to achieve perfect spacing.
Being absolutely centered should be down via screw B, right ? I will get back to you with hopefully some better if not a 'problem solved' message ??!!
Screw B allows to finely adjust the arm so that it is at all times parallel to the sensor arm. This adjustment is a bit iffy, you will find that one tenth of a degree will change the arm's behaviour. It is properly aligned when the stylus always remains parallel to the sensor arm, but also when, just after cueing, it immediately places itself in that parallel position.
Then, the worm screw will move by about one third of a turn (or thereabouts) at every revolution of the platter, depending on groove spacing and speed.
Adjust the shutter's idle absolute position first (loosen screw A).
Hello jacques,
After a break I am back on the job - some good and some bad news:
The 4.6 procedure was indeed fiddly but I finally managed to get the servo working in the correct direction.....so far so good
But i have now a buzzing noise when the arm is lowered - at first I suspected the typical earth hum problem but I can't figure out what is going on ???
I am using the MMC4000 cartridge which should be compatible ?! Something is definitely causing that interference, but ......?
Frankly I would not have a clue which fault to suspect ? With all these tiny wires it looks like the famous needle in the hay stack problem or am I wrong ??
There is a part which may or may not remotely be connected to the problem ?? But, who knows ? I attached a picture
Any thoughts or suspects to be named ??
Cheers, alf
I have attached a picture
Good work!
Yes it is very fiddly. Now you know.
The humming can be solved. The MMC4000 is probably the original cartridge, so no problem here.
Do you use a B&O amplifier? Or an adapter of some sort? Has anyone chopped the original cable?
Hi Jacques,
Good to hear from you:-)
Yes, the adjustment was a nerve-wrecking experience.
I connected the table to a Braun R4 receiver via a DIN-RCA adapter where the buzzing noise appeared - first squeezing in an additional piece of wire, connected to the earth terminal of the receiver than connecting without the wire - no difference!
Next step, connecting the table to a Beomaster7000 without adapter: very low-volume signal here, so I had to crack-up ththe Beomaster to its max volume-setting to hear a decent signal, however it sounded very tinny without bass but no humming or buzzing sound ??
All cables seem original, nothing looks like chopped-off.
I tried to up-load a pic of a part which may or may not be at fault......however this is a wild guess of mine !
Trouble is the net or software as I am having problems with the pics upload.
The part I am referring to sits right there were the signal wires are attached to a small board, makink the connection to the DIN output cable - this grey part has 0.047K 250V written on it and looks like a cap ??
Again: buzzing sound appears with all eqiupment other than Beomaster, not the typical low-frquency hum !!!
Connection to Beomaster is very low in volume and almost without any bass in the signal ?????
Hope the upload works this time
The mystery part I was referring to is a grey cap, mentioned in the SM section 6.6, #146
Can this be the buzzing noise causig culprit ??
Using a Beogram6500 with my beomaster7000 I never thought about not having a built-in phonostage:-):-)
This fooled me twice - thanks for telling me !!!
As for my buzzing noise problem I did put a wire between the two DIN plugs without any success, so I took your advice
And got in touch with Steve to get a 'proper' one, hopefully solving the problem.
In the meantime I did discover some objects in the chassis - the two springs for the cover bolts and one mystery item
That I can not work out where this might be missing ??? nowhere to be found on any of the explosion-drawings ????
I took a pic and will -again - try to up-load :-)
Who can solve the mysterious part ??
Looks like one of the taps glued to the underside of the aluminum surface panels.
I was thinking that too.
Alf, your photos are too big!
'Proper'adapter are on their way - fingers crossed it will be the solution ?!!
Sorry about the too big pictures - I thought a simple tab on the link on top should show the pic in a decent size ?? But I shall choose a smaller size next time.
as far as that mystery part goes I am afraid I am not sure whether I understand what you mean ?
Is it absolutely necessary ??
I would like to understand where it should be !
Could you post a pic for better understanding
thanks martinand jacques :-):-):-)
There!
Thanks martin and jacques :-):-):-):-)
I had to laugh out loud, those parts were in the other room since been taken off - so I
Never looked at those !!
Of course there is one missing on the big one.
You two must know these machines inside out - thank you, now I have a few more good sleeps until the adapters arrive.
I will report back
enjoy your day gentlemen
ALF
Those ovely adapters from steve arrived........great gear but it did not help my problem with that buzzing noise - all is properly conneted and I still can not figure out what might be causing that.
Again I have attached a pic in the smallest possible version - as soon as the double spring-contact next to the solanoid opens the buzzing noise is on !!
I understand the reason for that could be many, a start with good quality adapters has been made but what next..........??
I can operate those two spring-contacts by hand when the table is still turned off - the moment they open the buzzing noise is on!
Absolutely no idea :-((
Regards ALF
Next
The contacts just earth modulation when the arm is up. Leave them alone.
Check your internal cabling, perhaps inside the Beogram's DIN plug, or at the cartridge's connector.
It is amusing in some ways that experts and interested amateurs can think alike!
The damn DIN plug was the only thing I would have checked next - however I feared an internal fault at first - and bingo, something wasn't right in that DIN plug, just a bad connection or sodering joint !!
It finally plays without any unwanted noise - halleluja !!!!!
Thank you so much for staying with me patiently - very much appreciated :-)
Now the hunt is on for securing a replacement arm-wand for my other beogram4000
Wish me luck - if you have one for sale you could spare please let me know
Well done!
Sorry, I do not have any spares. I'll keep watching for you, so good luck! Enjoy your working Beogram 4000 then!
No worries jacques,
Just let me know if you come across one - silly me missed out on a non-working beogram4000 for a hand full of €€€.
Will enjoy mine for sure:-)
Best, ALF
Perhaps you could actually show us your decks Alf?
We do love pictures here!