[Q] why can I do to fix my galaxy s2 charging issue? topic

My galaxy s2 is not charging with the original charger. It doesn't even recognised by the computer. It shows the charging icon for 5 seconds but automatically goes away. I want to flash the mobile. But the computer won't recognise it. I also tried to download stock and custom roms but it fails every time. I also tried to download with torrent for mobile but it didn't work. It charges when I shut off the mobile and switch on again and plug in the charger instantly.*I have reset the mobile several times, wiped data and cache, deleted the battery stats, changed the battery and charger several times. I am using Android jellybean 4.1.2. I think it is a software problem. Someone please help me.*Thanks in advance.what can I do to fix the problem? I