Galaxy S3 Mini screen seems to get touched when there's no actual touch I have a Samsung Galaxy S3 mini which I've bought about 6 month ago. For about 3-4 months now, I've noticed when looking at its screen (but not touching it myself) that there's things happening on it as if some invisible finger would touch the screen:


lock screen with pattern would report some random touching on one of the screen lock pattern's circles. It looked like someone did a short finger-drag of about 1 cm, and then would shake the finger very rapidly on it:





other times, when I was doing stuff on the phone, it would either open an application or the Google tool-screen (the one that normally opens when you hold the home button for a longer time on Android 4)
also, while it was doing this, if I tried to override the ghost touches with my own finger the screen wold be very unresponsive (it would only "get" parts of my inputs)


I've googled for a solution and I've found basicaly 2:


1: remove the screen protector and clean the screen well to make sure it has no moisture or hand-desinfectant gel etc. Did that, removed the screen protector, wiped it good with soft paper, still have the problem
2: some people said that if I'm charging it with something else than its own charger, it may lead to the problem I have. It's true, I'm using multiple chargers to charge this phone only one of which is the original charger it came with. I've tested this, and it does appear that the problem arises when I charge it with an LG charger, or when I connect it to my laptop: before connection, no ghost finger, after connection, when the lock screen display automatically, there's the ghost touch like in the screen shot. However I'm not 100% sure that it's ONLY when I charge it like that that the problem crops up. However this does seem to be one way to trigger the problem.


My question is then:


has anyone had such a problem also? If yes, did they found a solution that fixes it completely (i'm willing to factory reset it if necessary, buy some fancy cleaning kit, etc)
if the solution is to only use its original charger, how come it seems to happen when I connect it to laptop also? How am I supposed to make it so that it doesn't go all ghost touchy when I want to transfer my pictures to my laptop?
My opinion is the screen might be grounded with some metallic or conductive object inside the phone. Probably a loosened part due to use. You can try to wave a strong magnet (like neodymium) at the back of the phone. Data shouldn't be affected anyway because flash chips are resistant to magnetism. But its still much better if you can get it repaired thru warranty.