Hallo Lapet,

sind weitere Beolabs angeschlossen?

Andere Zuspiel Geräte?

Antennen Kabel?

Könnte ein Masse Potential sein.

Hallo,

war da nicht mal ein Problem mit dem Display? Versuch mal die Helligkeit etwas zurückzunehmen.

Gruss nanoloop

Please pardon my German, but I think you said "surren" - "whirring"?  My BV10 *always* makes a whirring noise -- it has two fans inside and one never stops spinning!  But you also said the whirring was "transmitted" even if you use the 3.5mm headphone jack:  By that, do you mean electronic noise, "hissing", coming out the speakers on the front of the unit?  It's easy to determine, because fans sound louder if you put your ear near the back of the BV10.  Replacing a noisy fan is a simple repair.  Of course if the board temperature rising is just causing the fan to speed up, that's more difficult.  My BV10 whirring noise is audible because it's mounted on the wall, which makes the fan echo really well, and also drives up the temperature inside the unit, more than if it were stand-mounted.  

(If I misunderstood and sound is coming from the speakers, oops, sorry to waste your time.  Random guess in that case is power supply noise which tends to permeate all analog audio signals but leaves all the digital stuff mostly untouched.  Screen high frequency noise, typically from the backlight, is similar.  But in both those cases, the whirring should be coming through the 3.5mm headphone wires too.)

Thank you trackbeo, 

 

after all my troubleshooting I think it is the power supply. But I am not sure. If I switch thru the channels the hissing is for the moment away (1 sec) until the picture is showing. I think I need to buy a power supply and test it out.

 

Any other recommendations?

You say the hissing goes away *until* the picture syncs, when changing channels?  In that case I would bet that the power supply is OK, and *not* the cause of the noise.  Beyond that I do not know: alas, maybe it is time to ask for help from your service tech / dealer.  If I were debugging in your place, I would test whether the hissing also goes away when switching *sources*, both to a source that is up and running and providing the HDMI signal, versus to a source that is powered down and thus nothing shows up but sooner or later the letters "DTV" (or whatever the source) appear at top, and the screen is displaying even though it's black.  I don't know what that would mean, but a competent technician might.

(@nanoloop might be correct about the screen backlight being the source of the problem, but you can't reduce it to zero else you wouldn't see anything.  Obviously my fan suggestion was wrong, because, for example, you can hear a short whir from the fan during power-on, when your hissing presumably also will not be present because the display has not yet powered-up.)