I have decided to put my BL3500 time display investigations on hold - grandson visiting this week hence study/workbench reverts to spare bedroom.  I have unplugged the power from the BL3500 several times, and each time I reconnect it has to wait until 'on the hour' to start showing the clock again (consistently 7 hours and 20 minutes behind British Summer time).  This time signal can only be coming from the BC2300. Hence I don't have time to take the back off the BC2300 and put it in service mode - I am not sure that this would reset the hidden clock anyway.  I think maybe quickly shorting out the backup battery (while the unit is unplugged from mains) may well reset the clock, but might also clear the FM offset, and it was a bit tricky to reset this when I replaced the battery so I'll give that a miss. But that got me thinking: If there is a hidden clock/timer in the newer one-way IR BC2300, then perhaps B&O just got rid of the two-way IR circuitry, hence it's impossible to adjust the clock or set a timer with the Beolink 5000 remote?  However, MCL equipment does support 2-way IR.  So what about connecting my BC2300 via PowerLink to a BeoLink passive (ML/MCL converter) and connect the speaker terminals by MCL cable to an MCL2A (or 2AV) plus IR sensor, and then see if I can use my Beolink 5000 to adjust the time? I had a quick look at the circuit diagrams and can follow the BC2300 PowerLink pin 6 (also Aux pin 6) to the extra 'MCL' pin on the Passive's Left speaker terminal, and then all the way to the data connection between MCL2A and its IR sensor, so perhaps there is a way to shortcut this process by connecting an MCL IR sensor direct to the BC2300 to give two-way IR? Anyway, I had a very quick look through my B&O box pile and haven't a clue where my Beolink 5000 is, so any of the above tests are a non starter until I have time to find that.  More to follow!