I purchased an iPhone 4s on eBay. The phone is as if permanently locked in 'Searching... ' mode (the top left hand corner of the display). The phone is not connecting to the Internet, or the WiFi, and neither does it seem to connect to phone services through the SIM card inserted. And while the phone is in this state, it is heating up on the right-hand side, with display facing upwards, and gets drained of battery in about 40 minutes, even when it is in standby mode.
I have replaced the battery, and then the antenna, but to no avail.
What could be the problem? Please help!