[KolfMAKER]

@Luke

Thanks for your extensive response.

I have now also read the thread about the BeoLab 6000 with power on off issue. And the comment by Steve Saunders and his modification suggestion:

• Power-link mode: Mount a 1 nF capacitor across 03D1.
• Line mode: Mount a diode 1N4148 between 03R126 and 03D19.

But I think that further on in this thread, he mentions that this modification only goes for the BeoLab 6000 with serial number up to 10500000. Which is quite old.

 

Concerning my own BeoLab 8000 with which I started this thread … It is currently dead, not responding at all to power. No red light, no relay clicking. So I am a few steps back, to get it back alive again first.

 

Concerning your PDF of the circuit and marked suspect problem components, hard for me to judge. But I am very interested to hear what others like Steve think about this.

 

Hope this thread continuous!

[KolfMAKER]

Hi A2bur,

Some checks on what mentioned:

1. ”Powerlinks tested with working speakers” – Does that mean that when connected via Powerlink, all speakers do switch from Stand-by/Off to On?
2. If they work with Powerlink, is your issue of not switching to On, with the RCA/Line input?

What you mention about sponge, probably is about the foam: fallen apart and sticking to PCB’s and components. If so, this is a common problem and you will have to clean everything out.

This foam rot can cause shorts or even eat away parts of the copper traces.

can you share pictures of this?

[KolfMAKER]

I have:

• BeoLab 4000 – 2x
• BeoLab 6000 – 4x
• BeoLab 8000 – 6x
• BeoVox 600 -2x
• BeoVox 1200 – 2x
• Grundig AudioRama 7000 – 2x

They are positioned throughout my house, so I use all of them.

My daughter will get the BeoVox 1200 set.
I also used to have a pair of S80 with a damaged coil on the mid tone driver. But after repair and restoration I gave them to my son.
(B&O throughout the family!)

[KolfMAKER]

Thanks @ Die_Bogener, for your recommendations.

What I did next:
I swapped the PCB01 TRAFO board from a working BeoLab 8000, into the troubling unit. I kept the other unit the same (PCB02 Power Supply & Amplifier board).

 

Result:

• No issues with Auto stand-by, just smoothly switching from ON to OFF/Stand-by when it should.
• When the BeoLab with this (swapped) Trafo board is on, there is also no noise/buzz.
• When I touch the 5-pin cable when the BeoLab is ON, there is some noise/buzz.
• When I touch the 5-pin cable when the BeoLab is OFF, it does not cause the BeoLab to switch to ON.

 

Conclusion:

The amplifier seems to be fine. But the Trafo board/PCB 01 must be having the problem.

 

Question:

Since the voltage measurement (see earlier post) on the T2 trafo shows a non-symmetric load (20 Volt vs 23 Volt):

• Is the T2 trafo the problem source, or could it still be some other part or component on PCB01?
• If T2 has to be replaced, what is a good source to find a (reliable & affordable) replacement?

[KolfMAKER]

In the meantime I found this circuit. This seems to be a audio signal monitor that can push a trigger signal to switch an amplifier from standby to on.

Does anyone have experience with this?

 

Power supply voltage: DC 3V-15V

Standby current: 3V — — 0.7mA, 5V — — 1.2mA, 12V——3.3mA

Output:

• AUD1A: output high level 3mA or low level 3mA. A high level is detected after the effective signal is detected.
• AUD1B: output high level 1500mA or open circuit state. A high level is detected after the effective signal is detected. The output terminal has protective diodes, which can be directly connected to various loads (including inductive load).

Sensitivity: Audio or video signals with an amplitude not less than 180 mVp-p can trigger work effectively (the actual video signals are all 2V-2.5v).

 

Pin configuration:

• VCC— — power supply positive electrode
• Vo— — output terminal
• AVin— — AV signal input terminal
• GND— — power supply negative pole

The potentiometer in the lower left corner of the module is used to adjust the delay time, and the clockwise adjustment time is extended.

Be careful: Even if there is no audio/video trigger signal, the circuit will output a high-level pulse signal at the moment of power-on, and then enter the normal working state.

 

 

 

Productinfo and descriptions can be found here.

[KolfMAKER]

I have now been able to do some measurements on PCB 01. I did the same on another PCB 01 from a different well functioning BeoLab 8000, and put them side by side. It looks like this:

On the left side of the blue dotted line, the well functioning BeoLab 8000:

• Left/red = measurements in stand-by/Off mode.
• Right/green = measurements in On mode.

On the right side of the blue dotted line, the BeoLab 8000 with issues:

• Left/red = measurements in stand-by/Off mode.
• Right/green = measurements in On mode.

 

---

---

So compared, what I see:

• T2 shows 20 and 23 V, so not even.
• Else, I see no differences.

 

Question

Is there anything that we can conclude from this, that helps towards a solution?

[KolfMAKER]

Thnx Guy!

Do you have a link to an example of the Playmaker?

By the way, do you know of any DIY kits, or boards that I could use for self-build integrations?

[KolfMAKER]

Sounds Heavenly’s products are great, no doubt.

But (in this case) I am especially looking for something that works automatically: sound coming in, speaker switched on.

[KolfMAKER]

Thnx @trackbeo

Ok, let’s check if I understood correctly what you mentioned. This is what I took from it:

• So as soon as there is 5 volt on pin 4 of the Powerlink connector, the amplifier will switch from OFF to ON.
• As long as one wants to listen to music, the 5 volt power (to pin 4) should remain active.
• In this setup there is no automatic ON/OFF switching of the amplifier. The amplifier switches ON when the 5 volt power source (connected to pin 4) is put ON. And the amplifier will switch OFF when the 5 volt power source (connected to pin 4) is put OFF.

 

Question

1. Are my points above correct?
2. If they are, how can I create a setup that automatically switches ON & OFF via a Powerlink input, when the audio source is non-B&O?

[KolfMAKER]

Many thanks @Guy, @Mr10Percent and @Steve at Sounds Heavenly !
Very helpfull information.

Just for my understanding …

Is it a matter of:

1. The PowerLink connector gets 5v continuously, and an incoming audio signal is the trigger
2. The PowerLink connector gets 5v as a short trigger (e.g. fraction of a second), caused by incoming audio.

 

I try to understand how the trigger function works.
E.g. If one takes the BeoLab 8000 and connects via the RCA input, the trigger is the audio signal coming in via the RCA.

[KolfMAKER]

New checks & tests

I have just swapped the PCB01 TRAFO board from a working BeoLab 8000, into the troubling unit. I kept the other unit the same (PCB02 Power Supply & Amplifier board).

Result: no issues with Auto stand-by, just smoothly switching from ON to OFF/Stand-by when it should. Also no noise/buzz.

So something must be wrong on PCB01 the Trafo board.

[KolfMAKER]

Hi @Frog

Maybe the info in this thread helps:

https://beoworld.dev.idslogic.net/forums/search/MLGW/

 

By the way, searching is quite easy. If you click on “Forums” in the main menu of Beoworld, you will see the search field.

 

[KolfMAKER]

OK, at least you now know how to search.

[KolfMAKER]

Thnx Die_Bogener!

The issue of Auto stand-by clicking On-Off-On all the time, even happens when having no audio source connected to PL or RCA/Line in.

What about that ?

[KolfMAKER]

@Matador: thanks for sharing the leaflet!

@Geoffmartin: check.

[KolfMAKER]

Thanks @Matador!

Very interesting document. Thanks for sharing.

[KolfMAKER]

Very interesting @geoffmartin!

Great that you respond to this topic, as you have a lot of access to things. So very much appreciated that you like to share.

Is it possible that you share some pictures of what you describe as white and black sleeve versions?

 

PS.
Is this the Technical Sound Guide you are referring to?

https://tinyurl.com/4a72t56v

 

[KolfMAKER]

Interested to know more about what this is.

Is it a record, what is on it?

[KolfMAKER]

Thanks a lot Die_Bogener !

I now also noticed following. I touched the solder connection of the Left/Right signal wire (see red circle), with a screw driver. And immediately, the power switches ON. And when it is on, the hum/buzz gets stronger. Same happens (obviously) when I touch the back of the RCA connector (as it is the same connection of course). This does not happen when I touch the GND connection.

Concerning your advise to test by measuring (before plugging in the RCA):

• The voltage between source and 8000, both AC and DC
• Measure ground to ground
• And signal to signal

Just to be sure, do you mean …

• Ground & Signal at the RCA connector on PCB 05, at one side?
• And Ground & Signal at the P4 connector Amp PCB, as the other side?

 

[KolfMAKER]

That’s a real nice model. To be honest I did not recognize it first hand, but after a bit of searching I found it.

It’s the BeoLit Teena 609 AM, from 1962. AM only, battery powered, plastic casing, available in 4 colors.

 

Reference links:

• https://beocentral.com/beolitteena609am
• https://www.radiomuseum.org/r/bang_beolit_teena_609_am_exp_iii.html

BeoLit Teena 609 with FM: https://www.radiomuseum.org/r/bang_beolit_teena_609.html

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