My Lumia 640 Win 10 won't turn on. I hear vibration but screen remains black. What do I do?

[Windows Central Question]

My Lumia 640 win 10 wont turn on. I hear vibration but screen remains black.

So the issue started two days ago after I swapped the battery (40% charged) of my lumia with other 640's which had 9% charge in it. After that phone wont turn on. There isn't even a backlight to the black screen. And if I put my lumia to charge, it keeps vibrating at regular intervals (usually 10 seconds). I'm on latest windows 10 build. I also tried fully charge battery but it was no use. Please help. I tried many things written on forums, but I can't seem to fix it. I bought it in USA Best Buy but now I'm far far away. Can't claim its warranty from here.

 

[Maurizio Troso]

Re: My Lumia 640 win 10 wont turn on. I hear vibration but screen remains black.

So the issue started two days ago after I swapped the battery (40% charged) of my lumia with other 640's which had 9% charge in it. After that phone wont turn on. There isn't even a backlight to the black screen. And if I put my lumia to charge, it keeps vibrating at regular intervals (usually 10 seconds). I'm on latest windows 10 build. I also tried fully charge battery but it was no use. Please help. I tried many things written on forums, but I can't seem to fix it. I bought it in USA Best Buy but now I'm far far away. Can't claim its warranty from here.

It seems a faulty battery for me : check copper pins, maybe are bended , short circuited, or dirty.
Clean usb port and plug too
Then plug and try a soft reset.