update here. i have since sent to service centre and got my phone mobo replaced. the wifi & hotspot are working again but sadly i found that my back cover is slightly damaged. It must be caused by tools used to open the back cover. also, my screen protector was taken off which is understable but now i need to go through the trouble to get a new one again. im now very worried that the new mobo will become faulty again one day. i am now on A11 and i dare not upgrade to A12 at the moment.