Why is my charger not working after installing a new display assembly?

Hi,

i have a 13" Macbook Air mid 2013 A1466 that started having display issues to the point where I couldn't use it

i ruled out logic board problems because everything worked when I hooked it up to an external monitor. I also unhooked the display and made then external monitor run off my MacAir like it was the main monitor and everything worked.

So, that's when I knew what part to buy to fix my notebook. I bought a new display assembly from Amazon & used ifixit.com to change the display out. After installing the new display everything was working perfectly fine & was pleased to know my laptop was back to normal UNTIL I tried to charge it & the charger stopped working & I couldn't charge my mac (I had no charging issues prior). Im worried I did something wrong in the process of installing. I opened the back of MacBook Air & I did notice the I/o board to logic board flex cable wasn't flat so i made sure it was secured properly & it worked!! I was so relieved!

But, almost a week later Im having the same problem! It was taking the charger earlier that day but I unplugged it & planned to charge it later but I waited too long & was down to 1-2% & when I plugged it in, I didn't notice right away it wasn't charging before the laptop died on me. I can't get it to charge again. I get the same problem with no green / Amber light plus this time my display will show the red battery to connect a charger symbol. Of course, I did check the same flex cable but this time it didn't fix my problem. I haven't had another charger to test out to see if its my charger but I doubt it's my charger. I do feel it has to be a problem I created when installing the new display. I did not have charger issues before.

I am thinking of going thru all the steps of uninstalling the display to see if I can fix the problem that way but I'm nervous when I'm not specialist & although I do have a little knowledge to where I did feel comfortable doing this myself to begin with, it was mainly to save money from what apple was quoting me.

Before i try tearing my MacAir apart, Im hoping to find anyone that may have some advise or suggestions to help fix my problem.

Thanks,

D