[Galaxy S6 Q&A, Help & Troubleshooting] Mark67222:
I've sent the phone back to seller.

I'm beginning to doubt myself though after this nightmare. This is going to be a long story....

When the S6 arrived I had to cut my micro sim down out of my S3 to nano size. I'm quite a perfectionist when it comes to stuff like this and did a good job. Though as the S6 didn't hold a signal I went into 3 store for brand new nano sim. Put it into the S6 instore and it was the same. Though they said wait up to four hours for it to register properly. Went home and after 6 hours still no luck. So I decided to try it in my S3.

This is when the nightmare began.

As I needed it micro size I cut out a template to put nano sim in. When trying to insert it in I wasn't happy. So I tried to take it out and the tip caught hold of the sim reader pins and came away. So I had a bit of plastic stuck in sim reader. Boy could I not get it out. So had no option but to buy a new sim/Mem card reader. Local shop wanted a tenner for one. Had no option so bought it along with a proper nano to micro sim housing and went along home.. Fitted it and then went along to the 3 store armed with both S3 and S6 to make sure I could either get the S6 working and if not get the sim put in the S3.

This is where my next dumb moments was. So I didn't lose the nano to Micro template I partially slotted it into the S3 sim reader.

Got to 3 store, explained S6 wasn't working with new nano sim and asked if they could check the sim was ok. They tried it in a HTC and it worked fine.

So this to me proved the S6 was faulty.

So I asked if they would put it into my S3 to show it worked ok in that.

So they went to put the Sim in my S3 and couldn't get the template out as i'm not sure if they pushed the sim converter all the way in!! As no sim was in the template the pins had hooked onto it. So ended up damaging the sim reader again. Jesus!!

So no working phone again. Just an apparent working nano sim.

Got home ordered ANOTHER sim/mem reader.

To get me connected I ended up taping the nano sim in place on the S3 and part of an old credit card on top so the rear cover put pressure on the sim as well. This was after cutting away the top part of the original sim reader to get the plastic out and to expose the pins. LO and behold it worked!!! Full signal just like I normally get and H+ data

So I've had a phone for last 24hrs working and got home tonight to find the new sim/card reader had arrived. Thought wow that was quick delivery. Took sim out and thought i'd give S6 one last try as I install the new sim reader. . Still no luck getting stable signal so boxed up S6 to return. Put sim into S3 with proper template AND you'll never guess what........ITS DOING EXCACTLY THE SAME THE S6 WAS!!!!

S3 now keeps dropping signal and going into emergency only calls. I'm thinking why didn't I just not touch it.

So is it possible that the 3 network throws a Dummy every time you swap sim into different phones??? Its just strange the S3 is doing excactly what the S6 was. Or could the S6 be upsetting the sim?

God i'm really baffled as there always seems to be more than one factor into the equation of whats wrong.

Now I'm just waiting to get hold of another sim to try or just hope after leaving my S3 on overnight it might settle down.

God phones....I hate em LOL