Galaxy A3 SM-A300FU dead need a help please

Galaxy A3 SM-A300FU dead no power not entering into recovery menu and black screen. When i connect The Phone into Power Bank is charging i can see it in power bank and when I connect it to PC the device manger shows up as Qualcomm HS-USB QDLoader 9008 (COMX). The previous owner told me he leave the phone in wall charger and is dead. I don't beleeve him I think the phone is Hardbreaked but I am not sure. Can some one confirm me and how can I repair it ? and thanks in advance for your help!