@green36821 just to clarify, there were no issues with this phone prior to the disassembly. It functioned as should and now it does not. If that is correct, it sounds like there is either something that is not connect right. You will have to open it up again and check all the connection. Make sure they are properly seated and that there are no bend or broken pins.
It is also possible that this is a software issue. Which is less likely since your phone worked before, Let us know what you find out.