i bought a curve 4 from someone sometime ago after using it for a while, it developed the following problems.
it started offing and restarting itself at random times.i reloaded the os from 7.1 to the latest 7.1 ,the problem got worse.i downgraded and reloaded the os to the first version of os version 6.which i got from bb official website.be these problems my bb catches only 3g it doesnt get edge.i was told it was battery problem.i bought an original c4 battery.the day i started using the battery ,the restarting reduced from every 15mins to every 50mins, although it restarts when i try to open some websites and sometimes when i try to download anything. the phone started recognizing only mtn sim cards.if i put another simcard in it ,it will after searching for network write sos. b4 i started using the new battery i could use any simcard on the phone.even when i tried using the old battery again the sim problem remained.now i dont know what to do, i have given it to few engineers but they couldnt do anytin about it.the phones carrier is MTN. advice needed.thanks in advance.