Problem with Lg 2753V Monitor (Front panel)

Hi everyone, i have problem with Front panel sensors on Lg 2753V monitor. Simply no sensor works, i can only power it of from cable, and i have no controls over it... So,my question is, what should i repair? there must be a little board behind those sensors... I think that should i replace,but can be something else a problem? And if it is a board,can someone tell me which i should buy and where (amazon.de,ebay.de...)?

Thanks in advance!