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ARCHIVED FORUM -- April 2007 to March 2012
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This is the first Archived Forum which was active between 17th April 2007 and 1st March February 2012

 

Latest post 06-11-2009 12:06 PM by Peter. 8 replies.
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  • 05-08-2009 1:44 PM

    • rgs218
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    BM8000 Tuner Issues

    Hi all, I could do with a bit of technical advice on a Beomaster 8000 which I bought on impulse at the weekend on Ebay. It had been listed just minutes previously, had no photos on the listing yet, and was described simply as 'used but working'. I'd been looking for an amp to put in my bedroom for some time but had rejected the idea of finding a working 8000 on my budget, so when this popped up with what I thought was a reasonably cheap buy it now price I didn't hesitate (I may have had a moderate amount of alcohol at the time that assisted the decision! Stick out tongue). The seller then sent me some photos and it all looked OK so I paid up and kept my fingers crossed it wouldn't be destroyed in the shipping here from Holland where it was located.

    Anyway, it arrived this morning and it seems to have survived the shipping intact. Cosmetically it is in good, but definitely not mint condition - nothing that takes away from the amazing appearance of this unit though. I have plugged in my Ipod and it sounds fantastic through my newly refurb'd RL140s. All the LEDs are working, as are both sets of speaker outputs and the inputs for other components.

    However, there are a couple of potential issues I've identified. I'm not sure if the slider controls for the bass and trebble are working as I can't hear much of a difference when they are adjusted. If I've understood correctly, this can be a problem on these units - is that right?

    More significantly the tuner seems to be behaving very strangely Hmm! It's quite difficult to describe what it's doing but I'll give it a go. I've plugged in an aerial from an old Philips system of about the same vintage which used to be my Mum's. However, I cannot get it to lock onto any radio stations. When you adjust the frequency wheel on both manual and automatic tuning settings nothing comes through until you hit 91.7 and then a random radio station sometimes comes through. I've had Radio 1, Radio 2 and a local radio station coming through clearly, but all with the frequency reading 91.7. Having got a radio station coming through, if I then adjust the frequency and come back to 91.7 again, you either get a different station, or most of the time nothing at all, and you then can't pick up any signals at any frequency. In other words, it seems totally random whether it picks up signal and when it does, what signal that is. What makes it even more confusing is that I can't get it to repeat the same 'behaviour' a second time. It always does something slightly different. At one point it was just going rapidly through random stations without me even touching it, and the display wasn't changing!

    It is obviously capable of recieving radio signals, and it can't be a lack of signal as my BM5000 which is currently right next to it picks up all the main stations fine. I have asked the seller about this and he says that the tuner was working fine before it was shipped, with all 9 presets tuned to dutch radio stations. So either I am doing something really stupid (quite possible!) or there is a problem with the controls for the frequency.

    Can anyone shed any light on what this might be? It doesn't bother me much as I hardly ever listen to radio, but it would be nice to know the unit was fully working.

    Thanks in advance, and sorry for the rambling message, hopefully someone will be able to make sense of it!

    Rob.  

     

     

  • 05-08-2009 2:03 PM In reply to

    Re: BM8000 Tuner Issues

    rob,

    congrats on the 8000! just got one myself recently...

    rgs218:
    However, there are a couple of potential issues I've identified. I'm not sure if the slider controls for the bass and trebble are working as I can't hear much of a difference when they are adjusted. If I've understood correctly, this can be a problem on these units - is that right?

    make sure that you press the "filters" button under the panel... the word "filters" will display when they are actuated.

    also, do the sliders seem to have some resistance? if not, they may be off the tracks.

    regarding the tuning issue (and the sliders)... i and another member had very similar issues and it was solved with the fix at the end of this thread.

    • B&o bottle opener
  • 05-08-2009 3:25 PM In reply to

    • rgs218
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    Re: BM8000 Tuner Issues

    Thanks for the reply Jeff. That's solved the slider issue - I knew I'd be forgetting something obvious!

    As for the tuner, the symptoms you had sound slightly different to mine. If I understood correctly you had two issues, 1. initially you couldn't get the frequency to change on the display when you turned the frequency wheel, then 2. when you solved this, you couldn't get the beomaster to remember the radio presets, or the correct start-up volume (if I've got this wrong forgive me, I'm not very technical!).

    Mine does something different - the frequency wheel turns as it should and the frequency display changes correctly as you turn the wheel - it's just that it doesn't seem to have any major effect on what frequency the tuner actually picks up. Also, it is remembering the frequencies that I set on the 9 presets fine (and the preset start-up volume). In fact it still had the exact settings of its last owner stored on when I recieved it. Of course, there could be a similar cause for both our problems. Hopefully someone else will have had a similar issue...

     

     

  • 05-08-2009 3:34 PM In reply to

    Re: BM8000 Tuner Issues

    rgs218:
    Thanks for the reply Jeff. That's solved the slider issue - I knew I'd be forgetting something obvious!

    well, honestly... i did not find it (filters) that obvious when i first got mine, so welcome to the club Laughing

    rgs218:
    If I understood correctly you had two issues

    that is correct... and they were unrelated!

    1.) my tuning wheel would not (still does not) work.

    2.) i later started having all sorts of whacky issues with the presets that i had established. the "tuning" was utterly possessed!

    i would not say that our issues are absolutely identical, but based on your comments and the simple bridging of board 9 in the other thread, i'd say you have nothing to lose.

    i am sure more people will be along in a bit! keep us updated!

    regards,

    • B&o bottle opener
  • 05-08-2009 9:09 PM In reply to

    • geearr
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    Re: BM8000 Tuner Issues

    Hi Rob

     

    From your description of the symptoms, I get the impression that the tuning dial and the displayed frequency output are working well, ie, if you switch to Manual tuning, you can ramp up through the entire scale from 87.5 to 108.  It also appears that you can “store” any of these settings and call them up again using the appropriate pre-set.  In that case, it appears that these signals are getting screwed up on their way to the front end tuner circuits.

     

    Since loose cable connections have been a source of many issues on the BM8000, you could look at some of these inter-board connections that may have come loose in transit.  I would start by checking the 5 core ribbon between PCB9 plug 85 and PCB2 plug 9 and the coax connection lead between PCB9 plug 84 and PCB1 plug 2.  These are fairly easy to get at for a good “clean and wiggle”.  Make sure that they have a fairly tight fit.  See if that changes any of the characteristics of your tuning problems.  At the same time, you could also examine the two board interconnections between PCB1 and 2, P6 and P7, for faulty solder joints.

     

    In the meantime, as Jeff has mentioned, you might as well update the links on PCB9 as that has the potential to resolve all sorts of tuning related issues.

     

    Good luck

     

    Geoff

  • 05-09-2009 6:23 AM In reply to

    • rgs218
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    Re: BM8000 Tuner Issues

    Hi Geoff, thanks for the reply. Your analysis seems very plausible, and as you say the fact that this problem seems to have developed during shipping seems best explained by loose connections. I'm in the midst of university exams at the moment so unless someone has a simpler explanation it sounds like I'll have to wait a few weeks before I can take a proper look inside and decide whether this is something I dare to try and fix myself or whether it needs some professional attention.

    I'll let you know how I get on when I get round to looking at it.

  • 05-15-2009 6:16 PM In reply to

    • richtoy
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    Re: BM8000 Tuner Issues

    Hi Rob

    I had exactly the same issue on a BM8000 I restored 2 months ago.  In my case if you spun the tuner wheel it would eventually move the frequency but if was not controllable i.e. it was always close to one end or the other of the tuning range.

    The problem in my case was in the control circuit that exists between the CPU board and tuner (IC5 on the CPU board which is a frequency divider to be specific but some other failure in this control circuit would also cause similar symptoms).  You will need the service manual and an oscilloscope to faultfind this area and if you have a CPU board type with soldered metal casing then you will also need patience and good soldering skills to get into the CPU board Whistle  There is a block diagram in the service manual that may help and section 11 contains tips.

    Keep up upto date with your progress...

    Richard

     

     

    Some of my B&O: BV3/32, MX7000, MX5500, LX5500, MX4000, BM8000, BM6000, Overture, BL8000, BM6000 Quad, BM4400, BM3400, BG-CDX, BM3000, BM1001, BM1200, BM1600, BM1700, BM1500, BM1400, BM2400, BM2300, BM4500, BM4000, BVM70, BVS45-2, BVS60, BC7700, BM2200, BM1900, BG8002, BM1202, BVPenta, BVP45

  • 06-08-2009 5:58 PM In reply to

    • rgs218
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    Re: BM8000 Tuner Issues

    OK finally got a chance to have a look at the 8000 over the weekend. I managed to get it open and have a look inside at the circuit boards but couldn't see anything obviously wrong, i.e. no obvious loose connections.

    Richard, your symptoms sound exactly like mine, however I have no experience in electronics repairs and I don't think this is the machine to start learning on! Getting it open and puting everything back together was challenging enough for me! However I did manage to sort out some of the minor cosmetic issues like realigning the outer panels which were a bit wonky and getting rid of the bits of dirt that had got lodged under the lcd display cover.  

    As I don't listen to the radio that much, I think I will just live without it for the moment and just use it as an amp (which is what I bought it for anyway) until I get a chance to take it to a professional repairer. Is Tim Jarman the best person for that?  

  • 06-11-2009 12:06 PM In reply to

    Re: BM8000 Tuner Issues

    Yes! He has worked on mine in the past! I didn't realise you were an 8000 fan - I had the MS150s in the sitting room as well as my M100s.

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