Thanks for your replies,
I've recorded a couple of videos (one a couple of days ago, one today) of the problem. Yesterday my phone was perfect! No sluggishness, no delay in unlock, battery life lasted from 4am to 6pm (double what it has been).
Now today its stuffed again. I left the battery off charge from 11pm last night (was freshly charged then) and it had run out by 8.30 this morning (all it was doing was sitting there! I wasn't even awake). And my swipe to unlock is slow, sometimes i just can't use my phone for a few minutes as it won't let me unlock it/ turn screen on.
I put my phone on charge, and it said that I was on 20% charge after a couple of minutes, but then it started going down.. didn't appear to be charging at all, maybe coz the processor was getting axed?
These are the videos.
1, with standard unlock mechanism.
2. with pin number mechanism this morning
Can anyone help me diagnose this?? It must be a rogue application or something right? Problem occurs on both samsung and other launchers. At present, I've turned my phone into flight mode, and it is now charging normally (and quickly) and the screen is responsive once again, does that give any clues??
thanks in advance for your help, this is really putting a downer on my new expensive phone purchase!!