I recently purchased Motorola L6 and was happy with it 3 or 4 weeks. Then, it seems that my phone suddenly lost its sensitivity to radio signal so it looses connection whenever I come into some premises and frequently on the street between big houses. Its signal strength indicator shows 1 to 3 lines when other phones show 4 or 5. In my home, it shows NO SERVICE when other mobile phones, Samsumg and Nokia for instance, work fine. My claims were rejected 3 times in the local warranty repair shop because the phone worked in the shop. How to test the phone sensitivity and to make sure that it is defective?