The control system is two way,so when you press a key on the MCP,it sends data to the Beomaster,which is then processed,and data is then sent back to the MCP for display.

"no transmission" usually means that no data is being sent back from the Beomaster,but this could be due to faulty ir transmitter or receiver diodes in either device.

I think that you will need to 'scope the system to establish where the data signals are getting lost,but experience has shown that's it's quite common for the ir receiver in the Beomaster to fail,although I have seen cases where the ir transmitter diodes in the MCP have failed too!

Nick

Thank you for answering, Dom.

It's a good help to actually know that the devices don't need pairing.

The service manual does not mention this at all, which of course could indicate no pairing, but I became in doubt.

I will see, if I can find out how to check the IR operation by my iphone...

Never tried this before.

Best regards

Per

Thanks Nick for replying to this.

I will try to do some "scoping" as you mention :-)

I am a little bit rusty on this, as I haven't been working as a technician for the last 20 years, but I believe, the skills will come back to me again soon.

Will try to find the IR-components somewhere, it must be possible, still.

By the way, are you aware of a site, where I can download the diagrams in the original A3-size?

A4 is absolutely useful, but I sure prefer them in one piece, if you know what I mean.

Best regards

Per

It's a good tip about using a 'phone camera to test the ir system.You should at least be able to determine if the MCP is transmitting.The ir transmitters are located at each front corner of the MCP.

If you can see a blink via the 'phone screen when you press a key,it suggests that the MCP is transmitting.

If you can see a corresponding blink from the Beomaster,it will suggest the Beomaster is receiving and acknowledging,and that the problem is probably the ir receiver's in the MCP.

If there is no blink in response from the Beomaster,it suggests that the ir receiver there is not working,which is  the most common cause of these problems.

Replacement ir receiver diodes are readily available,but the transmitters are becoming scarce,but not unobtainable.

You might be able to find an original(paper) manual for the system among the many sites offering data.

The majority of course are simply scanned copies.

Nick

Thanks for the fine guide for testing the IR-function.

I have had a quick try, and the MCP blinks clearly from the transmitterdiodes in both corners, when depressing keys on it.

However, from the BM5000 there is no response at all from the three transmitting diodes.

I then guess that the natural conclusion must be an error in either the receiver or the transmitter circuitry on the BM itself.

I will check up on that tomorrow, haven't got the time today.

Thanks again, I'll get back with the results, when the BM has been tested.

Best regards

Per

Hello again.

Then it works nice and smoothly.

The problem was the IR driver transistor (IC2) next after the receiver diode (D1).

My oscilloscope showed signal at the base but nothing at the emitter.

A new darlington, MPSA65, did the trick (I didn't have the original SPS5431, but the MPS should function as well). At least it has done until now.

In the end, quite a simple problem to solve, but it surely helped a lot to be educated a little first :-)

So again, I will thank you both, Nick and Dom, very much for the kind help, you provided.

I really appreciate it.

Best regards

Per

Change the three caps at the displayboard for new ones.

Hi Beobuddy.

I'm not quite sure, what you mean by "displayboard".

There are three small pcb's behind the frontpanel, IR-board, LW, MW, FM indicator board and the last, that I would call the display board, containing the 4 seven segment displays.

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linkHowever, only the IR-board contains electrolytic capacitors, on the 7-segment board is only two 10nF ceramics.

In my experience ceramics seldom fails (although it does happen in rare cases), so I did not replace them.

I always (!) recap this kind of old equipment - it is my mistake that I didn't mention it before, sorry about that.

In this case I also recapped the IR-board as well as almost any other electrolytic in the BM.

Could you, please, specify, what you mean by the "displayboard" - and which three capatitors?

There are 5 electrolytics and a single .22uF polyester cap at the IR-board.

I should mention, too, that I did a totally cleaning of all the 18 small switches behind the fronpanel.

Afterwards they were all lubricated with a thin layer of contact grease.

Some job, and it took a lot of time, but now when it's done, it is nice to know that it will probably not be nescessary to take the prontpanel apart again.

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Best regards

Per

Hi, I know this is an older post but I have the same issue.

When replacing the D1 receiving diode do you use the daylight filter version or the standard one?

Many thanks

Jerry