Damaged IC RF on iPad Mini (1st Gen)

I've been having this problem since 3 months ago when suddenly I couldn't connect to the internet while my signal bar was full. I thought it was connection problem, so I went check to my provider and when they checked the nano card was fine. But I insisted to replace the nano card with a brand new card.

The issue still happened on the next day, I got full signal bar but couldn't connected to the internet while all my friends whose using the same provider as mine were okay. I've been doing anything such as restart network setting, restart device, hard restart device, and restore iPad. I did try with the other provider, many provider, yet still couldn't connect to the internet and having full signal bar. Until I eventually lost signal at all on my iPad. "No Service" all the time.

I've been checking some reviews about this and came to the conclusion of damaged IC RF. Well, it's not all damaged, but weak. Can you help me, do I have to replace the IC RF and if I do, where can I get it, and how much does it cost? Please, I really need your help..

Thank you guys, really appreciate your attention.