Beolab 8000 preventive care.

Viewing 13 posts - 1 through 13 (of 13 total)
  • Author
    Posts
  • #3705
    matador
    Moderator
    • Paris France
    • Topics Started 19
    • Total Posts 171

    Hi Guys,

    UPDATE: the foam in my pictures are not set correctly, good way to install them is as in the drawing below, in the center of the speaker, around the woofers.

    oce0fbpk6ai8oiycg0qh92t6zaxn3a63

    Unless necessary I will not remove the pictures to keep the process documented BUT REMEMBER THE FOAMS ARE INCORRECTLY SET.

    Apologies.

    This Beosystem 72-22 thing  did grew up into my mind to the point I got a pair of 8000 to make my own one.

    The recent old forum being still unavailable I would like to know if ALL BL8000 are prone to foam rot or if like the 4000 the did change the foam for a better one that do not disintegrate at a certain point? Mine are 12xxxx so 1997 I believe.

    Then is there something you can do appart from changing the foam,  I was thinking to insert a fine shit of plastic or whatever cut ti the shape to avoid acid dripping on the electronics.

    I know the way to go may be changing the foam but right know I dont feel like opening the speakers.

    Thank you for your advices.

    • This topic was modified 2 months, 1 week ago by matador.
    #3712
    KolfMAKER
    BRONZE Member
    • The Netherlands
    • Topics Started 9
    • Total Posts 49

    Hi Matador,

    Foam rot is a serious thing as it can damage the pcb and electronics, causing malfunction, etc.

    I am not completely sure about which serial number has the improved foam, but I think 12xx xxxx might still have the old foam.

    My advise for proper action is not to apply self cut pieces of plastic. This will not help, because when foam rot is there, it is already damaging the pcb and components. The only way is removing the old foam and thoroughly cleaning the pcb and components.

     

     

     

    #3778
    matador
    Moderator
    • Paris France
    • Topics Started 19
    • Total Posts 171

    Thank you for the comprehensive answer. Obviously note the one I was wishing the most!

    I’m good to open them and what I fear is the glue the seems to hold the front panels.

    I’ll do it as soon as I get or make new foam. In the meantime do you know if not using them will slow down the process (less heat) or as this nothing to do?

    #3779
    KolfMAKER
    BRONZE Member
    • The Netherlands
    • Topics Started 9
    • Total Posts 49

    Don’t worry about de-attaching the front panels and the glue strips holding them.
    Obviously, you will first have to remove all screws. After that, the glue strips will hold the speaker driver panel and the PSU/AMP panel in place. The glue strips function as gaskets.

    Nevertheless you can push a flat hand screw driver (actually & literally with a flat head), just underneath the panel, and push it up a bit. Do it slow, and as soon as it comes a Biot loose, move the flat head down a few centimeters, and so on.

    “In the meantime do you know if not using them will slow down the process (less heat) or as this nothing to do?”

    The heat inside the cabinet makes the foam deform. As Long as you do not use them, the process will of foam rot will not continue. Be aware though that the damage might already have been done. Some times, some of the copper tracks on the PSU PCB are eaten away. And sometimes that’s even hard to see with the eye. But this is easy to solve with some by-pass wires.

    #3780
    matador
    Moderator
    • Paris France
    • Topics Started 19
    • Total Posts 171

    Perfect, all I wanted to know.

    Thank you Kolfmaker.

    I Will update the forum when I’ll do it.

    #4411
    matador
    Moderator
    • Paris France
    • Topics Started 19
    • Total Posts 171

    Bought today two set of B&O white replacement foams: 10€ each.

    Even for a raddish like me it do not worth spendind time for DIY’ing an alternative solution.

    I will document the replacement operation here.

    PS: at least here in Paris, the most complicated step was to find a dealer selling spare parts. Most of the dealers don’t do after sales and can’t order parts references.

    #4415
    BeoFrederic
    BRONZE Member
    • SF Bay Area
    • Topics Started 2
    • Total Posts 14

    Matador, there is a series of YouTube videos that details the process of opening up the BL8000s.  It’s a good series — I used it myself to open both of my 8000s a year or so ago.

     

    The series was created by Pyramid Audio in Austin, Texas.  Let me know if you can’t find it, and I”ll dig for it.

    • This reply was modified 3 months, 2 weeks ago by BeoFrederic.
    #4443
    matador
    Moderator
    • Paris France
    • Topics Started 19
    • Total Posts 171

    Found it, Thanks BeoFrederic, it will help.

    #4464
    matador
    Moderator
    • Paris France
    • Topics Started 19
    • Total Posts 171

    Hi Guys, It’s done, at least for one speaker.

    The other one will wait a bit since this is not a really pleasant experience.
    That will also allow me to compare Both speaker with new and old foam.

    Starting point: the Beolab with stand and fret off and obviously the new set of damping material.

    IMG_9420

    Then take out the screws off: 6 for the amplifier plate, 12 for the speaker plate. All the same.

    You need to cut the rubber border use to damp the fret between the two front plates. Use a sharp knife.

    IMG_9424

    The plates are still firmly glued to the pipe. Insert a flat screwdriver and gently pry off the plate. Then progress to the bottom. I used two very useful little tools Thant came with a garden tinsel from a Scandinavian well known brand to open up the two plates, one side after the other.

    IMG_9425

    IMG_9422

    IMG_9426

    IMG_9427

    Disconnect all that should be:

    • One big socket between speaker plate and amplifier plate. (white/blue/red).
    • One big socket (main power/Yellow) between the amplifier board and the cone.
    • Two little connectors between the amplifier board and the cone (3 and 4 wires).

    Beware, there is also a third tiny connector much larger (7 or 8 wires), you can disconnect it but it loops from the cone into the cone. Don’t mistake it for the one  that must be disconnected and pull the plate while it is still attached.

    IMG_9433

    Once everything disconnected, take out the plates: amplifier first, then speaker

    Here start the mess! Use gloves.

    Foam to be removed is located:

    • Just above the cone.
    • One the amp board, between the actual amplifier chip and the main board.
    • In the gap between the speaker zone and the amplifier zone.
    • One big piece in the speaker tube.

    IMG_9428

    IMG_9438

    IMG_9431

    The big speaker piece was in my case quite well, sticky and chewy but I was able to remove it easily in one part.

    All the other parts were in an advanced state of disintegration, turned into a sticky dust spread all inside the column. You’re happy when you manage to take out a big piece!.

    IMG_9429

    IMG_9430

    Even the foam sealing between the pipe and the plates is rotted. you need to rub it to clean it.

    IMG_9435

    The pipe was vacuum cleaned with the help of alcohol (90°, no isopropyl here in France).

    IMG_9436

    IMG_9437

    The amplifier board was opened after disconnecting the plugs and cleaned with a brush and alcohol.

    IMG_9439

    To me this is the most scary part: I don’t like rub a brush on those PCB with so tiny component. I’m not confident enough to know if this is ok or not and I’l afraid of breaking something or hurting a component. SO I did this carefully with a brush and a vacuum cleaner, take out the most of it but after this, it still remain some sort of sticky touch all over the parts. I think it still better the before.

    IMG_9440

    IMG_9441

    Before screwing the amplifier board to the Amplifier plate, you need to replace the foam between the chip and the board.

    IMG_9442

    Then clean all the connectors, the speaker socket was particularly dirty.

    IMG_9443

    Then you can start the actual foam replacement. Note that the new set has nothing in common with the previous.

    Around the bas port entry.

    IMG_9444

    In the column, roughly in the middle behind  were the woofers are.

    6a89zo1ry0sn23mdkv28tpncapzgr06c

    At the base (rear).

    IMG_9446

    The V shaped one at the bottom of the long strips just above the amp section.

    Close the speaker panel and watch out for the speakers wires to go into the foam groove of the V shaped piece.

    7a9tiiqv7pzv4in25wrqvuq3w6n1563w

    Correct placement of the foam pieces is are illustrated below. They should make a coffin for the two woofers.

    oce0fbpk6ai8oiycg0qh92t6zaxn3a63

    Then, place the amplifier board, plug everything that need to:

    • One plug between amplifier plate and speaker plate.
    • 3 or 4 plugs between amplifier plate and cone.

    Before closing the amplifier plate, add the remaining front base foam piece.

    IMG_9450

    Close the speaker, tight all the screws (18) and check your new foam root proof Beolab 8000!

    Hope this helps.

     

    • This reply was modified 3 months, 1 week ago by Keith Saunders.
    • This reply was modified 2 months, 1 week ago by matador.
    #4929
    TWG
    GOLD Member
    • Topics Started 3
    • Total Posts 15

    Thank you very much for the detailed guide and photos!

    #5330
    Leosgonewild
    BRONZE Member
    • Topics Started 1
    • Total Posts 3

    Amazing documentation of the process, Matador. Great pictures 😀

    As you have written in other posts, the placement of the new foam in the column is incorrect.
    Would it be possible to replace the pictures in this thread in order to make this writeup correct?

     

    #5340
    matador
    Moderator
    • Paris France
    • Topics Started 19
    • Total Posts 171

    Done, Thanks for reminding this to me.

    #5341
    Leosgonewild
    BRONZE Member
    • Topics Started 1
    • Total Posts 3

    I can`t figure out how to send you this picture in a PM. But feel free to use this picture in your writeup. (and also delete our comments after it)

     

    IMG_1129

Viewing 13 posts - 1 through 13 (of 13 total)
  • You must be logged in to reply to this topic.