[ICHooligan]

Hello everyone, I am in need of some help. I inherited a Beomaster 4500 system with XTRA speakers set-up in the bedroom and the XTRA Speaker kit in the garage that runs up through the walls into the MCL 2A (pictures attached), with the house I purchased in mid-2023. I noticed in the wall that the wires for the MCL were spliced at one point and attached with sautered connectors. I moved into the house and was able to connect a 7DIN to the AUX port in the XTRA speaker kit that has a 35mm male end that goes into a bluetooth module that allowed me to utilize the XTRA speakers on AUX setting with the Beo1000 remote, which allows me to hear my Samsung TV through those speakers. However, after a few months, I decided to purchase a new MCL 2A and reconnect through the same splice as the buttons on the existing one weren’t working any longer due to wear and tear. It worked for a few seconds and I was able to turn it on with the remote, increase the volume, etc., however, once I powered it off, it never came back on. I tried testing the wires going into the MCL as well as the XTRA Speaker kit and found that it’s only getting around 2 volts, even though my plug is sending out 120 as it’s supposed to. I’m not sure what happened here or how to remedy it. There are no B&O dealers even close to where I live and this system is so vintage, it’s been difficult trying to find someone to help. If anyone has any clue what I can do here, I would appreciate it. These XTRA speakers are wired through the wall and mounted to the wall, so I feel like I want to use them, but with my current situation, I can’t. The red light on the speakers is lit on both of them, but the red light on the MCL is not lit due to the lack of power going into it. Existing wiring was not messed with, only spliced through the wall to connect the new MCL as the other one was spliced too and it worked for months til I disconnected it, just couldn’t use the buttons on it. Please help and thank you in advance!!

[Guy]

Hi and welcome to Beoworld!

The MCL2AV shown in your first picture should be powered by a 15V DC supply that usually comes from a mains adaptor. This little disconnected plug at the top of your first picture looks like it has become disconnected, so that could be your problem.

The MCL2AV will be getting some power (voltage) also over the MCL connections from the BM4500 (but not enough power to work properly), so that could account for the 2v that you have measured.

The UK mains adaptor looks like this:

[ICHooligan]

Thank you Guy and thank you for your reply. I actually have it disconnected currently and when I took the pictures, I had it unplugged. Attached is the DC supply that was plugged in when it was working and I assume it came with the product back in the 80s. Is this not enough and if not, could you point me to where I could purchase a new DC supply to replace it? I’d question why suddenly it’s not enough to power the unit, as nothing was changed with the system, besides re-connecting the new MCL 2A to it. This powered it all before and now it won’t. Thanks again for your assistance. Please keep in mind too that I’m in the US and would need a DC supply for US outlets. Hate to look on Amazon and grab one that’s 15V and blow it out. I appreciate your time, thank you!

[Guy]

I don’t recognise that model of DC supply but I am not familiar with what may have been supplied to the US market. I am surprised that it does not have a 15V output, but if it worked previously then perhaps 12V/500 mA was enough.

Have you measured the output of the DC supply with a multimeter? You might find that the voltage is a bit higher than the rated 12V. Despite stating 15V, the one that I pictured actually reads 23 V when it’s not connected to the MCL2AV.

If you do have to buy a replacement DC supply then make sure that the connector has the correct polarity; unusually the B&O one requires the centre to be negative, outer positive as you can see on the little diagram on both our adaptors. A good electronics store should be able to supply a similar adaptor to the one you pictured – I can’t recommend any particular US supplier.

Also check the connections inside the MCL2AV – the cable that comes from the BM4500 may have disconnected from one of the terminals. And check the connections to the IR sensor/transceiver that you replaced – are you able to refit the old (faulty button) one to see if it will see work?

I wouldn’t rule out a faulty MCL2AV – they do fail, and this thread is an example where madskp had to do some fault finding and repair: https://beoworld.dev.idslogic.net/forums/topic/mcl2-av-no-55v/#post-15498

[ICHooligan]

Thank you both for your explanations. I’m not real savvy in the wiring department. As stated previously, this system was wired into the house probably in the 80s when they did some additions. I purchased the house in 2023 and this system was left as it’s all wired within. There is the Beomaster 4500 with CD changer on the wall in the upstairs living room, with two towered speakers connected. That works fine no problem. Then there is one MCL2AV box in the garage that I assume is wired from the main system in the living room and then runs up the wall to the bedroom above where there are two square box speakers mounted to the wall behind the bed and the MCL2A sensor box also mounted on the wall under the speakers on the one side of the bed. All I did was disconnect the old sensor box and attach a new one, which worked initially when I connected it to the existing wires coming up from the garage from the MCL2AV, but then discontinued working after I powered it on, increased the volume, then powered it off. I’m not sure if could have shorted out the MCL2AV or what could have happened? I did all this with the MCL2AV unplugged. Once I connected the wires from the new or refurbished MCL2A, I went into the garage and plugged the MCL2AV back into the wall and it came on no problem. I came back up to the bedroom, powered the Xtra speakers on with the remote against the MCL2A sensor and was good to go, but once I powered it on and changed the volume, then powered it off, it hasn’t come back on since. I tested the wires in the MCL2AV and MCL2A sensor box with a multimeter and it read 2V. So something is lacking power, I’m just not sure what it could be. I’m no electrician or speaker system set-up guy to this magnitude, so I’d have no clue what to do in this situation. I’d try to replace the MCL2AV, but I have no idea where to get one. I tried Quality Dream Audio, which is where I got the refurbished MCL2A sensor box, but they do not have any in stock and not sure what I could get to replace it to ensure the whole system worked again.

[Madskp]

Just chiming in here with my 2 cents and a couple of questions

1. You do mention a Beosstem 4500, but I can not tell from your description if you have been using that through any of the xtra speaker kits? The reason for asking this is that the MCL2AV shown in you picture can work independently of the MCL system when you are only using it’s local input connectors as it have it’s own powers supply. Therefor it can work without the MCL cabling and the Beosystem 4500 for the use case you have describe.
2. You do mention that there is also xtra speaker kits in the garage and the bedroom. Are these the same type as the one in your picture? The reason for asking is that there is both an xtra speaker kit (where the grey box is an MCL2A) and en xtra active speaker (where the grey box is an MCL2AV as the one in your picture) and there are quite some differences in them.
3. Where have you measure the 2V you are mentioning? The MCL cable do supply a voltage of arround 8V in the pink vire from the main system (in your case the Beosystem 4500). The voltage can be measure between the pink and the brown wire. Some voltage drop should be expected along the cable, but 2 V seems low.

Here is the cable colors.

Do note that it is also important the the two speaker connectors are connected correctly on the Beosystem 4500. Left and right must no be switched as one of them caries voltage and the other data signals.

Also important that they are conencted to the speaker 2 terminal on the Beosystem 4500 as the speaker 1 connctors do not supply voltage for the MCL system.

If you have MCL2A boxes (Those without local inpus) these can only work if they get power from the Beosystem 4500.

Hope that these inputs can help you further. You are welcome to ask if any doubts

 

 

[Madskp]

Hello again. I have now re read the whole thread and I might have misunderstood which components are in your system.

If I understand it correctly you have the MCL2AV box in the garage, and the IR eye + speakers in the bed room?

The measurement of the 2V where did you take that at the splice?

If sio you could instead try to measure it at the screw terminals in the MCL2AV box to see if it has the correct voltage of 5V.

I should be done between the terminals for the green and the brown wire

Hope this helps

[ICHooligan]

Correct Madskp, MCL2AV box in garage, with the wires running up through the wall to the IR eye in the bedroom where the two square XTRA speakers are wired and mounted on the wall behind the bed. I took the reading of the outlet, which was 120V, a reading of the wires (green and brown) at the IR eye where they are soldered to the eye (2V), at the splice, (2V) and at the screw terminals in the MCL2AV box (2V). That’s basically where I am now, only 2V are being transmitted when I have it plugged in. Keeping in mind, I never tested previous to it not working, but when it worked, I assumed the voltage was accurately sending at least 5V to everything. Also, I’m not sure how the wiring is done for this system, but the red lights are on the speakers as we speak, even though the MCL2AV box is not plugged in currently. Assuming they are wired to the main system in the living room and the MCL2AV box is just an addition to let you run them with the IR eye and remote for additional sound in another room. The IR eye, when the MCL2AV box is plugged in, does not come on, as the red light does not even light up.

Again, I really appreciate this, as I mentioned before, there is no-one around here where I live that services B&O or would have any idea about it. I really wouldn’t care to bother with it, if they weren’t mounted to the wall, but since they are there, it was nice for a couple months to use those speakers with a bluetooth adapter and run sound through my bedroom Samsung TV. I really hope we can troubleshoot this and get it back up and running.

Maybe there’s something at the main system in the living room that I can reset or test to make sure there is accurate power going to the MCL2A box in the garage? I don’t know, as I’m not tech. savvy when it comes to this system at all, so anything you can suggest, I’m willing to try. If I need a new MCL2A box, that’s fine too, if that’s the issue or another IR eye, I would just need to know where I could get those items? This system is from the mid to late 80s, but it sounds and looks awesome, so I’d really love to keep it going.

Thank you!

[Madskp]

ICHooligan wrote:

but the red lights are on the speakers as we speak, even though the MCL2AV box is not plugged in currently.

The speakers are active speakers with built in power supplies, so they will always be in standby indicated by the red light if they are plugged into mains even though there is no source.

ICHooligan wrote:

Assuming they are wired to the main system in the living room and the MCL2AV box is just an addition to let you run them with the IR eye and remote for additional sound in another room.

I would assume that yes. That is the way his system was intended to be used, as a link room to the main system.

ICHooligan wrote:

The IR eye, when the MCL2AV box is plugged in, does not come on, as the red light does not even light up.

You could try to disconnect the IR eye from the screw terminal in the MCL2AV and try to measure the voltage at the screw terminal again. If it now shows 5V that would indicate that the problem is in the cable or the IR eye. If it is still 2V the fault is probably in the MCL2AV.

Also as Guy suggested you could try to connect the old IR eye again to see if that works

ICHooligan wrote:

Maybe there’s something at the main system in the living room that I can reset or test to make sure there is accurate power going to the MCL2A box in the garage?

I don’t think that is nessecary at this point. The MCL2AV should work independently even though the main systems is disconnected. The MCL2AV do not use the 8V power from the main sytem as it has it’s own power suply.

 

[ICHooligan]

Ok, thank you again for your reply. I have removed the IR eye wires from the terminals and tested where the brown and green terminals and it barely reaches 2V. I also tried reattaching the old IR eye as suggested and same result. I have a feeling something might have tripped when I replaced the new IR eye with the old one as it came on, then after powering it off, it wouldn’t come back on. Something must have triggered in the MCL2AV box or something?

Would you or anyone know where I could get a replacement?

Thank you!

[ICHooligan]

I noticed that Quality Dream Audio is out of stock on the one I have, but they have this one that I’ve attached. Would this work with my system? The only difference I see is the extra port for TV on it whereas the one I have only has the 3 ports, one being marked TV, which is the one that I use to relay from the bluetooth adapter to run my TV in the room above. Please let me know. I appreciate all your help with this, very frustrating.

 

[ICHooligan]

Thank you Madskp – Is there anything else I should consider? Do you feel that the MCL2AV is the issue and that replacing it should resolve? I’ll just disconnect the wiring from my existing MCL2AV and connect to the new one once I purchase and receive it. Then just keep my fingers crossed.

[Madskp]

I would not suspect anything else at this point.

[ICHooligan]

Oh one other question. I noticed when going in to order the MCL2AV, it has an option for Type Number: 2020, 2027, 2031 or 2026. I’m not sure which one to get, any idea on that? It looks like the one I pictured above with the extra antenna port you mentioned. Also, I will make sure the entire system is powered down when I re-attach after I receive it. Thank you again for your help.

[Madskp]

2020 is the one with the Antenna port.

The other ones are without. The differences lies in which setup type the where bought for and if the had the IR eye or not. For your setup it should not matter

[ICHooligan]

Great, thank you!

[Madskp]

ICHooligan wrote:

I noticed that Quality Dream Audio is out of stock on the one I have, but they have this one that I’ve attached. Would this work with my system? The only difference I see is the extra port for TV on it whereas the one I have only has the 3 ports, one being marked TV, which is the one that I use to relay from the bluetooth adapter to run my TV in the room above. Please let me know. I appreciate all your help with this, very frustrating.

Yes this would work the same. The extra port for TV is just an antenna cable pass through that was left out in the later versions of the MCL2AV.

 

[Madskp]

When you are going to replace it a piece of advise is to also disconnect the power for the Beosystem 4500 to avoid any risk of damage anything in the process

[ICHooligan]

I personally wanted to thank all of you that helped walk me through this situation. I purchased and installed a new MCL2AV 2020 version from 1987 from Quality Dream Audio and I am back up and running, so that was definitely the issue. I made sure the system was unplugged, I attached all the appropriate wiring to the new one, well refurbished, powered everything back on and I am again able to use the XTRA speakers, the remote with the eye and all is well.

Again, thank you all!

[Madskp]

Great to hear that you got it all working again 🙂

Even though it’s old the MCL2AV is a brilliant and versatile box in my opinion

[Author]

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