P2370 LCD generate buzzing if the brightness is less than 100%

[muhamadamru]

Hello :
i have the following screen :
http://www.newegg.com/Product/Product.aspx?Item=N82E16824001330
and i noticed that if i decrease the brightness less than 100% a buzzing sound heard from the screen , like zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz heard if i put my ear on the pack of the display.

i remember that i had this problem and i get  the screen repaired by somebody, now i want to know the cause  of the problem and to fix it if possible and i am writing here hoping somebody help me.

Thanks in advance.

[muhamadamru]

up

[EPTech]

Hi There,

It is probably an EL backlit panel which is in essence a ga discharge tube. That one needs a high voltage converter. The buzzing you here is audible noise coming from the transformer. Usually it is more prominent on lower duty cycles, when you decrease the BL brightness. The converter is usually a separate (narrow) PCB. They are  massively available. Sometimes there a multiple converters in a panel, they may also be combined on one PCB.

[muhamadamru]

any solution ?
like changing the capacitors ?

[muhamadamru]

thank you very much but i didn't understand a lot from what u said