Tablet PC with IMEI invalidity issue I recently bought a tablet PC, from a Chinese manufacturer.

Its IMEI is 315589840117903. It's showing invalid in India. Please check with this link:

IMEI Validation Check 

How I can solve this problem? I am unable to connect to internet and unable to make any calls.
The check digit of the IMEI is invalid, and usually the IMEI cannot be changed, or in come countries it can even be illegal.

For more information, see how the IMEI is formed and the check digit is calculated here, or see a related question here.

There are ways to recover an IMEI on Android devices, but for this you'd need a backup of some files from when the IMEI wasn't invalid.