Hi @smileyu2013 ,
Ifixit does not do repairs.
It is a diy repair forum where people can offer advice on how to fix it yourself.
Does the phone show any signs of life when you connect the charger to it?
What happens (if anything) when you try calling the phone from another phone?
Has the phone been dropped or gotten wet at all?
If the phone appears to be totally dead, then it will have to be opened, inspected and tested as to what the problem may be.
Here’s a video that shows how to open the phone so that you can initially check if there is any obvious internal physical damage or loose connections etc.
If doing all this seems too daunting, contact a reputable, professional mobile phone repair service and ask for a quote to fix the phone.