Could anyone advise to this problem. I have connected a MCL2A with its tranceiver (square IR eye) to my BM6500. The BM sits in a closed cupboard so I will need the IR eye/tranceiver in order to communicate with the BM. I am using a MCP5500 which is working fine (two way) in direct contact with the BM, but as soon as the cupboard is closed there is no more information on my MCP, only "no contact" is seen. However, I can still turn off the BM, turn on radio, aux, cd etc, but I can't for example change the volume?  (The BL1000 works fine with all functions when the cupboard doors are closed) So, there seem to be an issue with two way communication.

Anyone got any ideas what might be wrong? and how I would rectify this?

It should work as I have had a similar system in the past. Check the wiring to the transceiver - it may be a loose connection. If not, check the transceiver to make sure it is sending signal - use a digital camera to pick up the IR signal of the transceiver.

I'm going to check the soldering/connections in the tranceiver. How do I check if it sending out a signal with a digital camera? what am I looking for? many thanks.

Press something on the MCP whilst taking a picture of the transceiver - it should have a pink glow - the MCP will emit a similar ir signal as will any other remote. Digital cameras can see IR.

I opened up the tranceiver and all the soldering joints between the cable and the circuit board looks fine. However there seem to be NO IR signal from the tranceiver. Through my digital camera I can clearly see the infra red diodes glow up on command on all my remote, but nothing is showing from the tranceiver. Now, how do I tell if it is the tranceiver, or the MCL2A that is faulty?

Well the obvious answer is to try another one but I realise that that is not very helpful! Have you checked the cable at the MCL2A end?