Hi @alialawa
Could be that there's a problem with the charge port board. Hopefully it is not on the systemboard.
Here's and image of the troubleshooting flowchart from the Galaxy M30 service manual that may help.
Under that there is an image showing the location of the systemboard components mentioned by the flowchart. The picture on the left is a close up view to help identify the components. The picture on the right is a overall view of the board so as to show the location.
[image|2905888]
[image|2905890]
(click on images)
With a fast charger connected to the phone:
''If there is no 9V at the first step in the flowchart,'' try replacing the charge port board. Here's a [https://www.youtube.com/watch?v=hIt7mmJK_qo|video] that shows what to do. Replacement boards are available online. Just search for ''Galaxy M30 charge port board'' to find suppliers that suit you best.
''If there is 9V at the first step in the flowchart,'' follow the flowchart to find out what and where the problem is.
If doing this yourself seems too daunting, contact a reputable, professional mobile phone repair service and ask for a quote to repair the phone