Why my phone displays usb connector error

@debelamidhagsa The USB connector issue are most likely related to either the Sub PBA (charging board) or the flex cable coming of it, which goes to the main board. Check the flex (SUB flex) to make sure that it is properly seated.

I have not found any schematics to repair the Sub PBA board. That means you will have to consider replacing it.

As for your battery draining quickly, if it is still the original battery, it is most likely started to get depleted. Replacing the battery should resolve this. Of course, check your settings and ensure that you are running a power save mode do decrease power demand. Here is a video that shows you how to replace the battery

Here are the directions for a complete disassembly. You do not have to go through all of the steps to remove the Sub PBA board.

That Sub PBA board is widely available at many places like this one. This is just an example and not an endorsement. Do an online search and select a vendor that appeals to you.

The M30 has a few variants, SM-M305F/DS, SM-M305FN/DS (Global); SM-M305M/DS (LATAM/Brazil); SM-M305G/DS You have to make sure that you get the parts for whatever variant your phone is.

iFixit does not yet have any guides for this model. While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!