IM-A870L Radio Interface Layer broke down
Finally I found the answer to my problem!

I took my phone to another expert and he told me that the Baseband IC is gone and it is a hardware problem. He could fix it if I can get him the IC as it is not available in our markets because of being a rarely used korean phone.

This thing is confirmed by another forum post here:
http://forum.xda-developers.com/showpost.php?p=26827676&amp;postcount=4512%22

where they say:


  type *#06# , and IF you get message "imei null" or imei starts by 0049XXXX or 00000 it should be resolved by software .
  but IF nothing is shown when you type *#06#, that is a hardware problem or look at attached picture below. . 


When I dial this code on my phone, nothing happens, so it confirms that it is a hardware problem.

I will try to get the hardware component somehow and see if it works.

My actual problem is not solved but I got answers and atleast I am comfortable that I given it a try!