This unit has a fault sensor system,that automatically turns the unit off if a fault occurs,particularly in the main amplifier section.

Doe's your unit power up if the 'speakers are disconnected?

I suspect that you will need to investigate around the main amplifier.

Nick

Check the speaker outputs for DC.
Check the solder joints for the output stage darlingtons.

Martin

Thank you both for your quick reply. Although the relay RL1 seemed to function corectly, it makes sparks.All the buttons are working now.The new situation: the stand-by button has to be pressed for a few seconds with a rattling sound of the relay, before it's turning off. I think the relay had too much sparks and the contacts are worn. I need a new relay, but where can I find it. B&O calls it relay 7600032. Ofcourse they didn't  manufacture it. Which relay should I buy?

The relay will be fine.
The Beomaster will have a hard time going in to standby and it will act exactly as you describe, if the three tonecontrol lamps are wrong or burned.
They are used to bleed the 15V when going in to standby..
Check the lamps.

Martin

Hello Martin,

You're correct. Those lamps don't work. How do I remove the control panel. It seems to me this panel is glued with double sided  foam. Do I have to cut it away with a sharp metal ? or is there a hidden screw ?

Screws are accessible from below, under the aluminium front 'nose'. Take a look from the bottom of the 1900 (might have to remove the bottom too) - see underside of bottom panel for screw locations for that operation.

Front panel is easy to get out, fiddly (not difficult) to get back in. Careful not to bend the flimsy metal strips/forks and avoid scratching the dark pvc, when you store it away.

When you have the touch panel off, the lamp PCB's are easily accessible, fastened with two screws each.
The lamp 'housings' clicks right out from the underside of the PCB's, making it much easier to swap the lamps.

Thank you for the instructions. I have found the bulbs. These are common car dashboard bulbs. 12v/80ma T3 type. I'll get me some tomorrow

I don't know where you found those specs, but they are not correct. Even most servicemanuals give wrong specs (12V 1W I think is stated).
Look at the circuit for the tonecontrol lamps - they are fed close to 15V - this alone points to a lamp voltage spec higher than 12V, or they
wouldn't last long.

And they are not T3.
They are not socketed at all.
They have bare leads and are soldered directly into circuitboards, held by little metal clips.

Who gives out all this wrong info?

You can see the correct lamps here:

Hello Martin,

I took them out, the bulb says 12v 80mA. I assumed this was correct, but maybe someone changed them before???

T3 can be bought without socket, only leads.