BeoWorld North America

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

Dillen — Mon, 16 Aug 2010 16:08:34 GMT

No, you won't blow anything with LED's but many functions rely on the current
flow through the lamps.
The green tuning arrows would not work/indicate correctly.
The volume control could become erratic and/or unstable and the three tonecontrol
lamps form part of the 15V supply circuit in that their current draw is used
to drain the 15V when going into standby - a too low current draw would see
the Beomaster hard to set into standby, it would pop back on again with a series
of clicks if the pad was kept activated.
The source lamps are often critical in that the Beomaster typically refuses to
either change to - or change away from - a source where the lamp has an
incorrect wattage.
Symptoms can vary slightly from machine to machine but this is the general picture.
LED's were available when the BM1900/2400 was designed and built. One LED is
actually used.
LED's are nothing but hard working diodes.
They fail just like any other semiconductor and I've replaced about 7 or 8 standby LED's in
Beomaster 1900/2400's by now.
If B&O could have used LED's for this futuristic wonder of
a stereo receiver, they would have used real 7-segment LED displays instead of lamps behind
screens made to look like 7-segment LED displays.
New lamps of a good quality will last for years and it will look, feel and function
as the designer and engineers intended.

Others may not agree. Some modern repairers try to fit LED's in wherever possible, expecting them
to last forever.
You are free to make you own experience if you absolutely must customize something.
The above is mine, based on 35 years with B&O things.

Martin

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

Mark2000 — Mon, 16 Aug 2010 10:36:40 GMT

I'm actually wondering if they could be replaced with LEDs so they would never go out again. Since those are so low power there wouldn't be a risk of blowing anything out. Plus, they would be brighter.

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

Dillen — Mon, 16 Aug 2010 01:03:03 GMT

No problem but do yourself a favour and check the lamps first.
The lamps filaments become brittle with use and the unavoidable vibrations from servicing often
break more filaments.
The lamp kit is fairly cheap. I like to replace the lamps on all Beomasters of this type
when they come in for service here. New lamps will give fresh life to them all and also give an equal light output
and the new filaments won't break in transport/shipping.

Martin

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

Mark2000 — Sun, 15 Aug 2010 22:35:07 GMT

I actually have the working lights from the unit I tore apart. Would it be possible to get the disassembly instructions, even for a fee? Thanks.

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

Dillen — Sun, 15 Aug 2010 02:08:39 GMT

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

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

Mark2000 — Sun, 15 Aug 2010 01:38:17 GMT

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?

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

equalizr — Fri, 30 Jul 2010 16:47:22 GMT

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

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

tournedos — Fri, 30 Jul 2010 16:30:23 GMT

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 )

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

Dillen — Fri, 30 Jul 2010 03:38:22 GMT

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

Martin

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

equalizr — Thu, 29 Jul 2010 18:16:39 GMT

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 ?

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

tournedos — Thu, 29 Jul 2010 17:37:30 GMT

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...

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

burantek — Thu, 29 Jul 2010 17:14:42 GMT

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?

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

tournedos — Thu, 29 Jul 2010 17:07:00 GMT

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.

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

burantek — Thu, 29 Jul 2010 17:00:00 GMT

equalizr:
why does the phono din have more pins

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

Re: BeoMaster 2400 -noisy bass,treble, balance sliders/pots Need help cleaning /getting to them

equalizr — Thu, 29 Jul 2010 16:49:48 GMT

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 ?