I have a spare MCL2A I'm trying to make sense of in case I need it later. I tried it with a BM5500 I had lying around but ran into local room control problems... first of all, it works just fine with my Beosystem 6500 so there should be nothing wrong with the transceiver, the box, the cabling or my option programming.

With the 5500, the transceiver and the box seem to be working as expected - I can mute/unmute the local speakers connected to the MCL2A with either the transceiver buttons or a remote. However, the Beomaster doesn't do what I try to tell it to do - no volume control, not turning it on or changing a source... however, standby works.

Otherwise I could understand this if the MCL data interface in the Beomaster was broken, but how an earth can it then follow the standby command? Is there something Beomaster 5500 -specific in this setup? The BM is programmed to option 1, and the MCL2A to option 2 as they are supposed to...?

You may need a software update in the 5500. Earlier ones don't work in the same way as the 6500 - I had exactly the same issue when my 9500 was stolen and I was given a 5500 by my dealer as a stand in. Exactly the same issues which were fixed by getting a 7000!

OK, thanks - in that case I'll probably solve the issue by not installing the 5500 in an MCL setup   After posting, I had the sense to try with an MCP6500 through MCL (and putting an oscilloscope on the data line) and the BM isn't responding in any way on the MCL. In addition, it is only the long "all-standby" command that goes through.

The type sticker in the rear says SW 2.3, can anybody confirm whether this is too old for a link setup? It seems that this just might be an electrical problem as well (blown buffer transistor or a faulty MCU) but I'd rather not bother investigating further if it isn't going to work without an update anyway.

Funny that the Beomaster should be that old - it is white, and I thought that was a late addition in the series.

In Beocenter 9000s the Datalink support is indicated by a sticker on the rear panel. In my case there is the Datalink sticker but no software version, perhaps the original models (without Datalink) have software version sticker and after update it's replaced by the Datalink sticker?

I got a MCL manual saying the serial should be after: 05101264 for being ready for Beolink.

If not the 4IC4 needs to be changed. Order number: 8341051

Beolink label follows the IC and should be put back on the Beomaster when installed.

Friedmett:

I got a MCL manual saying the serial should be after: 05101264 for being ready for Beolink.

Great info, thanks. This is s/n 0682xxxx, so it might have a fault after all. Have to look into it. I guess the part number will be on a sticker on the ROM chip, so that should tell it for sure...

Well, what better way to pass time inbetween cooking than opening Beomasters. So here is the CPU module - and clearly the updated software ROM is there, so there must be some other problem.

Too bad the processor is not socketed, so I will not just try replacing it although I have 8031's laying around. TR3 on the preamp module will be attacked next unless I starve to death first...

There was no need to dig in the middle... I put the scope straight on the relevant port pin of the processor and the data from the MCL came cleanly all the way there. Nothing out in return, though. It could be that the output function of the 8031 port pin is damaged - but that still doesn't explain why the all-standby command goes through and is understood by the CPU, but nothing else is.

I could take the CPU to the office to meet the rework station and try another chip, but that would risk ruining an otherwise perfectly good Beomaster... I think I will close it up, clean this mess and just not care about the MCL... the attempt was purely out of academic interest to begin with

Could it be a tranciver error?

Maybe the wire connection in the relaybox is not good enough?

No, I don't think so - as I mentioned in the opening post, all that stuff works just great when I connect it to the BS6500.

Hello,

The serial of my BM5500 is 04849878, so I can't use it for Beolink with MCL2A ??

Or can I use it with the first version of it, the MCL2A type 2045 ?

I don't understand it very well, do I really have to change the 4IC4 ??

Thanks a lot for help!

Regards, Bruno Destickere

Well you do acording to what the B&O manual for 1989 says.

If it works straight away I can't say but try it. I do not have a early BM5500 but you don't loose out testing it allready.  

If the test says it works great please tell us about it.

If not you will need the software update. Ask your B&O dealer if it still can be done. 

It was still early days I guess with the MCL system when the BM5500 came out. It got upgraded from MCL82/30 to work with BM5000/BC7700 etc. The MCL 2045 was finished while the BM5500 were out hence the later upgrade for MCL.

Hello,

Thank you for your quick response !!

I would like to test it, but I don't have already a MCL2A (type 2045) kit.

Before buying one, I would first to know if it works... .  :-)

What is precisely the difference between the 3 versions: 2045 - 2046 - 2047 ??

Regards, Bruno

As far as I can figure it out its software upgrades and minor flaws corrected. The latest 2047 is the X-tra speaker kit that came out around 1990.