Charging cable is not getting connect

@sarwarpatil you didn't tell us if it blinks in a pattern. Use the SM to determine what the blink codes means. This could be a bad battery. Try this:

• Remove the Battery, the AC Adapter and any other device connected to the system. Press and hold the power button depressed for 60 seconds. After that reconnect your AC adapter and your battery. Try to turn your computer on.
• Press F2 on boot-up to enter the BIOS screen. Check the adapter status in your computers BIOS to confirm that there is no issue with the adapter.
• Run the diagnostics to check for any hardware issues.

• Turn the computer off and then restart the computer. At the Dell logo screen, start tapping the F12 key a few times until you see the ‘One Time Boot Menu’ appear. At the one time boot menu, press the down arrow key to highlight ‘Diagnostic’, and then press Enter to begin the diagnostics. Make a note of any error codes that may come up. Let us know what you find out.

You can download teh service manual for your computer from here use that for any further troubleshooting.