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Beosound 9000 – IR receiver repair May 29, 2016

Posted by Florian in Audio, Devices, Repair, World.
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I really like the design of most classic Bang & Olufsen stuff – but my favorite one is the Beosound 9000. Since I pretty much like to understand how all these technical devices we are surrounded with work, I usually take apart more or less everything in order to find out how it works and how to fix it… I decided to buy one to fix instead of getting a working one I might break. I did some “training” with other classic CD players before I bought an old and not working Beosound 9000 in order to see if I can fix it. I really admire the design, bit it did not take long till I started to admire the engineers even more… it must have been quite a tough job not only to make it work at all bit to make it possible to produce it in quantities.

First of all: There is a service manual for it which helps a lot with common issues and how to disassemble the device without breaking anything. B&O generally does a good job releasing service manuals for its devices. One important information from the manual is that without speakers or headphones connected the 9000 enters ‘mode 0’ which means that it does not take any input from the remote control. So I connected speakers and tried to enter service mode and change audio mode without success… from some forum posts I learned that the IR receiver PCB14 fails in some cases. Since I did not what to find a replacement I tried to fix it… and I had a lot of fun:

First I found out that PCB14 really does not supply any data to the controller board – it is connected with just three pins (ground, +5V and data) and there was no traffic on the data line at all. Unluckily the service manual does not contain a schematic of PCB14. So I started to find out how it is supposed to work… the receiver is built around a Vishay U2506B IR receiver – so I thought it would be easy to find out more using the data sheet of that one but even Vishay and its distributors do not seem to have one.  In the end I used a broken Beolink 5000 two-way infrared remote control to find out about the signals on the PCB. It uses a similar design and the same controller.

It turned out that it was only a single broken 22µF capacitor – it is marked in the image below.beosound-9000-ir-fix1

 

This shows the PCB with the replacement capacitor. It is a good idea to use a mechanically smaller replacement than I did because a long capacitor case has some potential to hit the CD drive sledge when entering position 6.

After replacing the capacitor the IR receiver started work again. It was necessary to change to mode 1 manually before I was able to enter service mode. The easiest way is to use a Beolink 1000 since it has a ‘Sound’ button for this purpose. Just press <Sound> <1> <Store>.

I have some more information about repairing this magnificent Beosound 9000… but that’s something for the next post.

Note to my readers: Please remind me to blog a little bit more frequently :-)

Comments»

1. Raymond - July 19, 2016

Same admiration here to these Beosound 9000 cd player, I just bought a cleaned MKI but the CD does not work, so is the radio. I am searching for service manual but no luck, wonder if you are having similar problem and any luck to repair it?

Florian - November 25, 2016

I do not know much about radio issues but the CD lasers are known to fail frequently. Original one are close to impossible to find… there are comparably chap replacements but their quality is not the best. But I had some luck repairing my MKI with these… I just had to get three ones in order to get a really working one.

2. Natha - October 12, 2016

Thank you for the write up, I Fixed my Beosound 9000 MK2 with IR receiver problems after reading your post. The capacitor is a 22uF 6.3V. I changed it to a leaded type for easy soldering, the Beo 4 remote only works if all the speakers are connected to power link connectors. If not you need to jump the pins 2 and 4 on both the power link sockets. this is written in the repair manual Page 5.4 Test Mode. All the best. Many thanks.

3. Joseph - November 25, 2016

Hello,
My beosound 9000 doesn’t react to my beo 4 remote control also. Could you please send me a picture for the IR receiver and the capacitor you replaced? I think the image on your blog is broken. Do you have some instructions on how to take the IR receiver out? Thank you very much for your help!

4. Florian - November 25, 2016

Hello Joseph, you are right… looks like WordPress decided to break that image – no idea what happened, it gets found bot does not show up.
Anyway I replaced it and its back…
Taking the receiver out is quite easy if you know how. Basically its removing the screws that hold the top plate and unplug some wires. You do not have to remove it completely – that’s the trick. The best is to take a look at the service manual. A PDF with the one for the MK3 is easy to find and the device is mechanically the same like the other ones.
And do not forget to connect a speaker or dummy in order to be able to get it out of mode 0…

Joseph - November 26, 2016

Hello Florian, thanks for your quick response. I am looking at the manual at this moment (I am almost overwhelmed…:p), are you referring the top plate to 9005 or 9006? do you need to take off the glass lid first? Sorry, I am still trying to figure out where I should start. If you don’t mind, could you please also tell me where I can get your recommended capacitor online?

Florian - November 30, 2016

Hi Joseph,
yes I think you have to remove the lid. If I remember correctly there was a section describing the steps to get access to PCB14. Not sure about the numbers – its the large one that needs to be moved a little bit. The most important step was to find and remove the covers of the screws on the back side.
Unluckily I have no idea where I got the replacement cap from… found a matching one among my collection of spare parts :) I suppose its a quite common one you can get from various manufacturers.


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