If the ADSL light is flickering, then there is a problem with the Telkom Cable.
If the Internet light is RED, then there is a problem with the Username/Password or the Service Provider account.
The Wireless connection is ONLY between the Router and your device. (Laptop, Phone or Tablet). The router is between the incoming ADSL Service and your device.
For basic setup, the other lights are usually not important for basic internet functioning.
If you require any further assistance, please feel free to call or Whatsapp me on (076) 085-6891.