ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hello.
I have a problem with my BM5000/MCP5000, as they will not communicate together.
The MCP is from another BM5000, but should this be a problem?
Do they need to be "paired" before use - and if so - how is it done?
When trying to use the MCP, it just lights up the message "No transmission", and nothing happens.
The MCP has quite new batteries.
In the BM I did replace the C8 capacitor, 100uF, as it was way out of value.
Also the C38 in the IR transmitter circuitry was replaced, but that didn't help either.
All voltages in the BM5000 is OK and without ripple.
The BM itself works just fine except for the above, but it would be nice to be able to adjust bass and treble.
This seems to be done only through the MCP.
Did anyone experience something similar - or maybe just know, what can be wrong?
Best regards
Per
Dom
2x BeoSystem 3, BeoSystem 5000, BeoSystem 6500, 2x BeoMaster 7000, 2 pair of BeoLab Penta mk2, AV 7000, Beolab 4000, BeoSound 4000, Playmaker, BeoLab 2500, S-45, S-45.2, RL-140, CX-50, C-75, 3x CX-100, 3x MCL2 link rooms, 3x Beolab 2000, M3, P2, Earset, A8 earphones, A3, 2x 4001 relay, H3, H3 ANC, H6, 2014 Audi S5 with B&O sound, and ambio
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.
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.
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.
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.
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.
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.
However, 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.
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