Xperia S LT26i - dropping signal/internet pages/ games


Oct 21, 2014
I'm using an Xperia S LT26i and the signal keeps dropping. I used this phone before I had a Z. The Z has gone so I'm back using my old phone. I thought the old SIM had perished and that was why the signal was dropping out constantly, ie games kept throwing me out & back to home screen, FB said I had no connection/service despite icons saying I had full service & signal. Web pages were hanging or timed out constantly too as if I had poor or no signal even though the bars show full strength signal. I'm on T/Mobile/ EE and have been for last 3 phones, never had signal issues before. I've put a brand new SIM, which works in another phone, but its still dropping. So, its def the handset. I don't really want to wipe the phone as other users with same issue have said it doesn't work! Any suggestions or is it Sony Centre time? Thanks