Hi Adam, Firstly I just amended you post to show the photo in the text rather than as an attached heic file (which some browsers struggle to display!) Secondly I am 99% sure that you will need a clock-enabled ML (or MCL) audiomaster in order to show the time on BL3500 - a videomaster may also work but I am not sure. EDIT:  I think early BS2500 (with the two-way IR) had the clock function, but to set and operate it you needed to use a two-way remote such as the BL7000 or BL5000.  The two-way BS2500 could be recognised by its IR window being bottom left of the unit below the moving glass doors, as shown below: Login to view image

My BL3500's are linked by Masterlink  to a BC2 via an old BV5. In my case the time has to be set on the BV5 and is then transmitted to the BL3500s. Graham

Thanks, Guy. You're right, I have Beocenter with two-way communication according to your reply. So when the clock gets reset? Is it possible that if I disconnect my beocenter from the mains exactly at 0:00 and connect it again then the clock will reset to 0:00? My BeoCenter doesn't keep settings (dead battery? NVRAM?) so it should "forget" clock setting the same time? Strange way to set clock, but I dont have BeoLink5000 :(

There is a Test Mode, but you have to remove the case and short-circuit the CD clamper switch for 2-3 seconds. Pressing 7 then deletes all preset programmes, but I think this just means radio presets rather than timer/clock function. I would have thought that a dead lithium processor backup battery would cause the unit to reset the clock.  As you suggest, try leaving the BS2500 powered down for a time (several hours, in case the battery has some life in it) and then reconnect to mains power, noting the time of start and then waiting to see what is displayed on the BL3500.