USB connecting and disconnecting continuously

[iamrobomaster]

USB connecting and disconnecting continuously without connecting OTG cable.

And when I am connecting OTG cable, it is not getting connected.

I have tried cleaning port with thin brush and have kept in rice to soak moisture but nothing has worked.

Please help. 

[iamrobomaster]

I am using M30

[Flintstone]

What are you connecting via the OTG cable? Maybe what you see connecting gives the problem also go to "get help" at the bottom of main page of this app ~> diagnostics ~> USB test see if that gives any info⁷