Pie medical scanner 100lc ultrasound switching problem

Can someone support me to solve the powering problem with the ultrasound model pie medical scanner 100lc. When the 'ON' button is pressed, it will make a buzzing sound and stop. Hence, It could not be powered. Please, help me with the service manual or an instruction to repair the unit. Thanks. My e-mail is roupecrowwn2006@yahoo.com