hiw @Kartheek_Thatikonda This sounds very similar I had:
So the power can come from the USB or through the AC. I suspect that the AC->DC power supply is either not working or not properly connected. If you did the repair yourself, I would recommend triple checking everything. I generally recommend writing numbers/labeling the connectors and taking lots of pictures prior to making any fixes which is probably not so helpful now! I hope this helps and I hope this is not longer needed since it’s been a while!