[KolfMAKER]

Thnx @Tignum, this is helpful!

I think the width of the allen screw is compliant to M4. I found a screw with a fitting thread, which has a 4mm diameter.

The length of (1) I think is correct. If I measure with a fitting screw, it goes into the speaker for about 1cm. So there should be 22.7mm sticking out to hold the bracket and have space for the washers and the spring.

The bracket thickness is 4mm, each washer is 1mm, so that takes 6mm. The spring then sits in a space of 16.7mm, actually a bit less when put under pressure. So I assume the spring in an unstring condition could be like 18-20mm.

I will now start looking for those parts.`

Location: The Netherlands

[KolfMAKER]

Thnx for responding and sharing your suggestion Auric.

Yes, I know about the foamrot issue. In this I did check all PCB’s, connectors, etc. for foamrot. Some copper traces have had a ‘by-pass’ already.

What bothers me is that at high volume/signal strength the Stand-by/On switching works well. But at low volume/signal strength it doesn’t.

Do you have any other suggestions?

Location: The Netherlands

[KolfMAKER]

Thanks again for your comments!

I have removed the capacitor, to check if this made a difference.
Result = no difference. Sound is the same, functioning of the speaker system is the same.

I will just leave it as is, without the capacitor. Probably better to avoid damage.

Location: The Netherlands

[KolfMAKER]

Thnx for responding Die_Bogener!

Answering your questions …

• Yes, the crossover network is existing and fully mounted.
• I am not sure if this is the standard work of B&O. I showed a picture to a former B&O repair engineer. He did not recognize this.
• The cap manufacturer I believe is different than what’s used on the PCB’s.

Location: The Netherlands

[KolfMAKER]

Update 2

Someone gave me the tip to reflow all solder joints on PCB05:

So I did. Again, the first 10 to 15 minutes, the auto stand-by switching worked well. But suddenly after that time, the repeatedly Off > On > Off > On switching started again. So still no resolution found.

Tips are welcome.

Location: The Netherlands

[KolfMAKER]

Dear Jessy1984.

I am experiencing a same kind of issue. (See this thread)

But I can tell that when the switch in the foot is set to Line and you have nothing connected, then it is quite normal to hear noise/hum. This RCA connector is very sensitive and when nothing is connected, it will act as a kind of antenna picking up noise.

I hope someone with more experience will respond to this or my thread. My feeling is there is an issue with grounding, but I am not sure where to look.

Location: The Netherlands

[KolfMAKER]

Update

• On > Off> On > … – When first powering up the BeoLab 8000, the auto stand-by switch works normal and switches from On to Off/stand-by after music stopped. But after some 15 minutes or so, the auto stand-by does not work normal anymore, and switches back and forth between On and Off. (Something to do with warming up?)
• High frequency noise – I found after thoroughly cleaning the track side of PCB01/02, that the high frequency seemed to have gone. But I know noticed that sometimes it is there and then it is gone for a while and returns again.
• Hum – The hum increase when touching the casing or AMP/PSU panel is still there

Location: The Netherlands

[KolfMAKER]

By making a check on the PCB with a loupe, I found two cracks.
After re-establishing the connection, the speaker works fine again.

Thnx!

Location: The Netherlands

[KolfMAKER]

Maybe BeoBuddy can help you (Utrecht area).
If you look for his name, you can send him a PM.

Location: The Netherlands

[KolfMAKER]

This is what I have (see attachment). It does not list 24xx xxxx. But I guess it will be like 2013 / 2014.

Location: The Netherlands

[KolfMAKER]

Danke @Die_Bogener!

Concerning foamrot, it’s no foam. I made a typo with the serial. This 8000 has serial 1711 xxxx. So a MKII, built with the new white foam.

I will check for copperline cracks and defect caps.

Any other ideas are welcome.

Location: The Netherlands

[KolfMAKER]

@vanlaren

Hi, with Arylic products you can use their ‘APC Workbench’ software to control the output (incl. signal strength) of the Arylic device.

Here’s the info link.

 

Be aware that this software runs on Windows only.

Location: The Netherlands

[KolfMAKER]

The early models including your ser.nr. have been built with a type of foam that deteriorates after years of using the speaker. The foam then falls apart, sticks to traces on the PCB, components and connectors. Potentially causing shorts.

 

Did you open up the speaker casing, to have a look inside and see if the foam has deteriorated?

Location: The Netherlands

[KolfMAKER]

Exactly, I am also happy to understand the working of the motion detection on this B&o system.

Probably helpful to other BeoWorld members.

Location: The Netherlands

[KolfMAKER]

I did not expect these notches to be the receivers.

But this makes everything clear.

Thanks Guy!

Location: The Netherlands

[KolfMAKER]

Thanks Guy & Beobuddy!

So this is what I get from your info:

• There are 4 IR-transmitters, 2 on each side. In the picture they are marked yellow. For the left and right side they are placed symmetrically to each other.
• The IR-receivers look like the notch shape in the red marking, but are in a different location on the side.

 

Question

1. Are there also 4 IR-receivers, 2 on each side?
2. Are the IR-receivers the ones marked in light blue?
3. If so, are the IR-receivers in the right side in the mirrored position to the ones in the left side?

 

 

 

Location: The Netherlands

[KolfMAKER]

Hi RaMaBo, thnx.

1. The inwards pointing notch, is that the top one in the picture with the yellow markings?
2. Does it mean one notch is sending light, and the other one is detecting reflection (a hand) of lhat light?

 

Location: The Netherlands

[KolfMAKER]

Thanks for sharing Guy!

I am helping a friend, so the BeoCenter 2300 is at a distance for me.

Anyhow, we found out that the sensors are in the black notches you marked with yellow.
They connect via two cables (with each three wires) into one connector. That’s the white connector in your picture with the two grey cables leading to it.

What is not clear to me, but I am juyst interested to know …

I believe the sensor in the notches is a LED. So I assume the sensor works with sending and detecting light.

1. So does motion detection for the doors work with a kind of light beam, and sensing the interruption by hand motion?
2. Does the sensor/LED send the light to the side from underneath the black panel? (So not straight forward, because the black panel covers the notch)

Location: The Netherlands

[KolfMAKER]

Thnx for this addition Keith.

You are right: the tracks are different, components are in different locations or positioned in a different direction, …

I hope someone has the right version of the service manual, with a diagram reflecting the pcb in the photo picture.

Location: The Netherlands

[KolfMAKER]

Thanks again Keith. Very much appreciated you are still willing to help me!

After having returned from abroad after a few weeks, I have immediately started testing what you suggested in your last message. I listed 7 components from your suggestion and picture, to be tested on a GND connection with the multi meter: TR9, R84, TR11, R81, C47, C65, TR7, TR8. I used the visual layout of the board in the service manual (see top part of picture below), to find the exact location of these components.

 

Here’s the results

First of all I could find TR9, R84 and TR11. Their location according to the visual layout in the Service manual and the PCB itself, was identical. These are the findings on these components:

• P7-2 <> TR9 Emitter = Yes, continuity
• P7-2 <> R84 = Yes, continuity
• P702 <> TR11 Emitter = No continuity on the Emitter, but Yes continuity on the Collector

With the other 4 components I found out that the visual layout from the service manual, and the actual layout of the board differ. So for them I am unsure what their location on the board is.

In the picture below you will see both layouts. In the top image I have marked the 4 components that I can’t match with the layout of the PCB. In the bottom image I have marked the 3 components I could find and which I tested.

Speaker info

• Type number = 6801 (B)
• Serial number = 1448 8372

Comments / questions

Maybe the results of the 3 tested components already give you a clue. Is TR11 malfunctioning and the cause?

What do you suggest?

 

 

Location: The Netherlands

[Author]

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