Picked up a working Beomaster 2400

It works fine but the treble, bass, balance needs some deox sprayed on it

I'm pretty good in electronics - does anybody know what it takes to get to the sliding pots to spray them

 I took off the bottom cover not much help there

looks like that plastic panel will have to be removed

I may just leave it to the experts to do

 Any help would be great

Thanks

Lee

Welcome to Beoworld !

The Beomaster 2400 is not the easiest machine to get in and out of.
The top alu lid and underlying plastic cover comes off as one part.
4 screws hold the black metal rail at the rear, remove it.
2 more screws are found under the alu lid, lift it up and off.

I only use deoxit (contact cleaner) in places where I cannot get it and clean
with a glass-hair brush.
You see, the problem is usually not the resistive tracks in the potentiometers
but rather a tiny pitting to the metal tracks next to them.
If you must use deoxit, make sure to wipe with a cotton bud afterwards but
remember that no contact cleaning agents remove the dirt, they only allow it to move around
until the agent dries and if you're lucky the contact cleaner wont add to
the mess (most do since not all of their content evaporate).
The potentiometer will often only work fine for a day or two after deoxit, then the
noise returns.
The slight abrasive function of the glasshair brush will remove (or smoothen) the
pitting and will provide for a lasting solution (years rather than hours).
Clean and dry is good.

Martin

Thanks

Thanks

Martin

I was going to ask you if you if you could call me but i see you are in Denmark I'm in the usa

I removed the 4 screws in the rear and the 2 right under the metal lid to each side at the ends

Then how do you then remove the lid ?

does just the cover of the controls (bass, trebble...) and the metal lid assembly remove or does the touch panel come up to

also do i have to remove the big tuning knob to lift up that area

also what is a glass-hair brush- never heard of it

Thanks in advance

Eric

equalizr:

I was going to ask you if you if you could call me but i see you are in Denmark I'm in the usa

Eric,

Welcome to BeoWorld!

I am in the states and have had several 2400's open... in one instance to install Martin's brilliant repair kits.

Where are you located?

Miami fl

With the rear metal rail off and the two screws under the lid removed, open the lid and
lift it up. The plastic grabs under the edge of the sloping front so will have to be eased out gently.
The tonecontrol slider buttons will come off with the top cover, the rest of the buttons will stay
down (but are lose).
The tonecontrol indicator screens should not be pulled out as they are very hard to push back
behind the sloping front lens system without removing it all. Instead clip them off the black plastic
sliders on the potentiometers (the bronze clips) and push them forward, in behind the sloping front
to allow for better access to the potentiometers.

Martin

Ok got the top it off and cleaned the pots and now they are quiet.

Now that I have a chance to listen to it- I get what sounds like a little 60 cycle hum on tape and phone inputs- I have nothing connected to them since I have no cables for that . I really cant tell if im getting it on fm as there is always music playing.

bad caps ? or hooking up and input to the tape or phone makes the hum go away?

When the volume is compltely off it goes away but when you get just past the first position for sound you can hear it on tape & phono

any help would be great here

Thanks

Eric

Good job on the potentiometers !
These wonderful receivers are worth keeping alive.

Open inputs will often work as antennas.
If the hum persists, even with a turntable and/or tape deck plugged in (respectively), the reason
is, no doubt, the old capacitors. (A kit is available).
The board mounted rectifier can also cause humming and/or operational glitches.
There's a B&O tech sheet suggesting a replacement rectifier but even the type that B&O suggested
here are occasionally found bad (suitable replacement also available).

Martin

cant seem to find the right pinout for the 5 pin din for tape input>Can anybody point me in the right direction so I can make a cable with a pair of rca to 5 pin din

to test the input-tried google but cant seem to find it

still looking for the pinout for tape input

notch at top looks like its 4 ,1, 2 ,3, 5 left to right ?

with 2 being ground I cant figure out if 1, 4 or 3, 5 are inputs for a cd or tape

Take a look at the phono input, they are the same and in phono the outputs are (obviously) N/C...

Or just try it and there's a 95% chance that your first choice is incorrect

Seriously, the input pins are 3 & 5. Don't ask which way they are located in which connector as I never remember, most of them have tiny numbers beside the pins at least on one side...

I never bother doing these cables myself anymore, I just buy adapters.

EDIT: Link to a good pinout site, including DIN audio.

so tape and pnono inputs are the same if i make a cable for tape i can use it on phono as well

Correct, but you'll need to take care of the earthing as well for a record deck. The separate earth connection from an RCA equipped turntable should connect to the metal sleeve of the DIN connector.

hmm my 2400 has a ground screw near the din plug- I thought i would connect the ground from the turntable to that.

 why does the phono din have more pins -even though I can use just my 5 pin at 180 degrees- does it turn stuff on wit the extra pins ?

equalizr:

 why does the phono din have more pins

That would be for a BG4004 that would function w/ the remote commander.

Oh yes, that ground screw should work just as well.

The extra pins are indeed reserved for Datalink control of compatible B&O record decks (Beogram 4004, 2400 and 2402 I think). Not much use with others.

tournedos:

Datalink control of compatible B&O record decks (Beogram 4004, 2400 and 2402 I think).

Good call on other BG's being possibly compatible besides the 4004. Though I have a pair of 4004's ...neither are connected to 2400's. I do have a 2404 and 3404 connected instead. My question is: Was this indeed Datalink? I thought that it either predated Datalink or was at least a peer?

I'm not sure (anymore) if it was actually already called Datalink, but it is indeed a different (much simpler) protocol than the one used in the later products.

I have a BG4004 but nothing link compatible to connect it to - I was planning on building a converter just for fun...

well I made the cable cut up an old midi cable worked out perfectly

small 60 cycle hum in background- bummer on tape and phono & fm

was hoping it would go away when i loaded up the tape input

no go

well it was most likely was going to ebay anyway

now it might be one of those for fix/repair for the right person with the hum

unless i fix it than i actually might keep it

anybody have any recomendations on which caps ?

In short, all the cylindrical ones on the boards.
And don't forget the rectifier.
The capacitor kit contains more than 60 components.

Martin

After going through Beocentral, I'm convinced that this old peripheral communication interface wasn't called Datalink.

As I said it's very simple - maybe two bits worth of information is sent with each command, so there are only a few possible operations. For example the Beogram 4004 doesn't have any kind of a microprocessor doing this, the commands are decoded by transistors and delay circuits. Decoding and interfacing with the real Datalink this way (or even with basic logic ICs) would take a silly amount of circuitry. Apparently it took a couple of years more for B&O engineers to embrace this newfangled microcomputing fad inside the Beolab 8000 components...

Although the first microprocessor had been introduced to commercial market already in 1971, and was called... the Intel 4004

(sorry for drifting so far from noisy sliders )

Well most likely it will go on ebay as working but with very slight 60 cycle humm

its a shame everytjhing else seems to work perfectly

 All displays, tuners fm1-fm 5 lights, tape input...phono light

Thanks for everyones help on this

I'm not going to start changing caps-if it was only two maybe but to much for me at this time

 A job for the right person

I have noticed that this thing is indeed very difficult to get in and out of. The mainbard being soldered to 40-50 wires that hold it in and keep you from the final screw that would take the touch controls off - if I'm looking at it correctly.

Several of my lights are out. Is there an easy way to get to these that doesn't require forcible and possibly damaging entry?

Usually, it is not necessary to remove the main board from the chassis.
Most components can be reached with a little help from suitable tools and/or lifting just
a corner of the board away from the chassis.

The lamps are accessed from above, though dismounting the front panel is done from below...
A lamp kit is available, containing a full set of fresh lamps of correct type and wattage.
The kit comes with detailed (dis-)assembly instructions with photos and (english) text.

Martin