MCL 2 Expander: Repair or Replacement

[markg2000]

I have a B&O MLC 2 Expander that appears to have gone bad. I have 7 X-tra Speaker kits in a Master Control Link distribution system. Four of the remote speakers stopped working and the red status lights have gone out. I examined the MCL 2 Expander and there is a very hot to the touch scorch mark on the expander board. I have since unplugged the MCL 2 Expander. (See the attached photos). Does anyone know where I can locate “new old stock” or working used MCL 2 Expander kits? Does anyone know of a repair shop for these MCL 2 Expander boards?  (I have BeoSystem 5500 components.)

[Guy]

Hi and welcome to Beoworld!

Check with the seller but I think this is what you are looking for:https://www.quality-dream-audio.co.uk/beolink/14012910.html

EDIT: Further to the above, I would of course do a full check of the rest of the MCL2 connections first – it would be quite easy for a single wire to become disconnected that would cause the problems that you describe (possibly the pink ‘dc power’ cable.) Also, as you can see there are not many components in the MCL2E – without having the schematics I cannot be sure but an electronic repair shop could probably replace all components quite cheaply and see if that cures the fault. I would also check the output of the PSU that you are using with the MCL2E.

[Guy]

There is actually a circuit diagram for the MCL2E within the MCL Service Manual, available on this site for Silver and Gold Beoworld Members. The MCL2E is a bit more complicated that I first thought – the components must be on the other side of the board in your photo. Basically it just provides a fresh 9.3V power supply (pink wire) for the downstream MCL2As, and also amplifies the data signal (white wire).

[Madskp]

Looking at the PCB drawing in the servicemanual the burnt spot could look like its above a diode. The diode could be shorted, but it could also have affected other components. The Diode is in the part of the circiut that amplifies the data signal

[markg2000]

Thank you for responding to my question, Guy and Madskp. I may have gotten lucky. I found a new-old-stock MCL 2 Expander on eBay.

New questions come to mind (regarding newer MasterLink products) after researching the MCL2 expander and refreshing my memory on the X-tra speaker kit. I’ll post a new question in the forum for the benefit of other members. Thank you again for your help.

[Author]

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