Good Day, Everybody. I have recently obtained used IPhone 4s and have been encountering the problems since than. Firstly, It started to heat very much during the usage of Mobile data and Wi-Fi, battery was draining very rapidly and reception of Wi-Fi and 3G signal was very poor with frequent drops of Mobile signal. I decided to check the remaining capacity of the battery, It turned out to be 70% and I ordered replacement and after replacing the battery noticed that there was no grounding pin below the battery connector. After some research I learned that this grounding pin is responsible for stability of signal. I obtained one and inserted it accordingly in proper place. Now, During the usage of Wi-Fi I notice NO abnormal heat nor rapid drain. However as for Mobile data, phone still gets very hot and sometimes entirely drops not only 3G but all reception. Can anyone advice, if you encountered such a problem and how can it be solved? And also phone gets hot after long camera usage too. IOS 8.4 Thanks in advance.