I just started having this same problem about 15 mins ago. I took the SIM card out, put it back in, and everything seemed fine for awhile. But now it's telling me that I have an invalid SIM again. I feel like this definitely has something to do with iOS 5.0.1 because this wasn't happening until I upgraded.
Just some more info, in case some Apple people are monitoring this and using it to track down the problem:
I disabled the SIM PIN... No change, still got Invalid SIM;
I used just the supplied 4S charger/cable... No change, Invalid SIM. (I even removed the bumper, just to make sure it wasn't affecting the cable connection somehow)
I tried placing a tiny strip of isolating tape over the SIM contacts that might touch the microSIM craddle, also no change.
So... I think I've run out of ideas other than doing a full wipe-restore, which I'm not to keen on doing...
A couple of times I caught the exact moment of the Invalid SIM message popping up, with the iPhone just sitting idly by, not connected to any charger, nor doing anything.
Also, the Invalid SIM message is now popping up more and more: when I got the new SIM it went ok for 3 or 4 dyas, then it started popping up every couple of days... then every day... and now it's getting closer to 3 Invalid SIM errors per day!
I can hardly trust to be connected now, and have to constantly glance at the iPhone to see if its "invalid" or not...
Hope the upcoming 5.0.2 fixes the issue.
Yet another thing I've tried today.
I've tried using the microSIM "tray" from my old iPhone 4, and strangely enough the cell reception seemed to be a lot better (from 3 bars went to "full strength"). Which prompted me to believe it could be indeed a hardware issue - although both trays are exactly the same as far as I can tell visually.
But, even with better signal reception, in the middle of the day I got yet another Invalid SIM error... so, there goes my theory.
It made no difference, although I can swear the strength indicator does change and is affected dependending on which SIM tray I use... weird, right?
A few more tests...
Having tried my old iPhone 4 SIM tray in the 4S, I noticed I had a lot less Invalid SIM errors, but I often would have no connection even though it showed bars/3G connectivity. When trying to place a call it would do nothing... then fail after a while; then show no signal; then searching... and then finally back to real connection.
Today, I did a few more tests: using a friends 4S tray and also his SIM Card. (Though, as you would expect, I wasn't able to try it for more than a couple of minutes - so, no real data regarding if it might be SIM related or not).
However, when placing my SIM card (which still had some parts "taped over", as some suggest) in his iPhone 4S - it couldn't even recognize the SIM card (which was working "ok" in mine).
So, I ditched the tape over my SIM card, and at least it was recognized in his 4S. When I put it back on mine (no tape) - it is now behaving just like it was in the "4" sim tray: meaning, instead of frequent INVALID SIM errors, I'm now getting the "no service/search/connection found" issue.
... Which leads me to believe this might indeed be some kind of hardware error - although it's very strange to vary with simple remove/reinsert SIM Trays/cards...
The only thing I noticed - at close inspection - is that the sim tray seems to have a tiny layer of material over the place making contact with the micro SIM (in my case, it actually touches the chip contacts), and in my 4S tray, that layer isn't as "perfectly placed" as it should.
However, if that was it - then it should have given no error when using my old iPhone 4 sim tray, which is "perfect" in that sense.
So... I'm still at a loss - still hoping that this is some firmware bug of sorts... but growing increasingly weary if Apple is actually giving a **** about all this - or simply ignoring it all. I was hoping the 4S to be my best iPhone ever (having all previous ones that were available in Europe)... and as it is, I can't even trust it to be always within reach of someone wanting to call me.
I was little bit thinking
Me and my two friends bought the same day iPhone 4S.
Mine is having these issues with SIM card after 5.0.1 update, and their DON'T
I have activated my 4S in the Apple Store. Everything was fine but for some reason I switched my SIM back to my older iPhone 4 and was using it for few days. Then I switched iphones so I put the SIM to my already activated iPhone 4S and I was starting having these issues of losing signal, and "invalid SIM" etc.
What was different what I did and what they did:
My friends did backup of their old iPhones, activated their new iPhone 4Ss, and did restore from backup and then HAVENT USED THEIR old ones ANYMORE!
And here is my suggestion:
Isn't there some security from Apple not to activate more than one iPhone with one SIM card?!
Maybe I am not right, but who knows:(
What are your experiences?
If anybody here activated with this "wrong" SIM card more than one iPhone, there is probably the answer.
Well, you might have a point there... I might have also done something of that kind, switching back and forth with my old iPhone 4. But, in any case, I had my 4S working perfectly for weeks... and only began having problems when I upgraded to 5.0.1.
Since then I have already switched to a brand new microSIM, and still have the problem. (Though I haven't yet done a full wipe-restore... as I've been delaying to try out the upcoming 5.0.2 first. If that update doesn't fix this, I'll have to try the full restore - and if that doesn't work either, and Apple doesnt even acknowledges the problem... the only remaining option will be to return it and hope they give me a new one.
fix for droping signal and a "Invalid SIM" it would sound really strange, like Magician, but it WORKED!!!!
0. Turn OFF wifi on ur iphone 4S
1. open the tray with sim card and hardly push with thumb to clean the golden site on ur SIM card (i did it three times)
and pushed back
2. Hold power and sleep button EXACTLY for 30s without stop!!! then start ur phone and turn ON wifi on ur iPhone 4S
3. tick Airplane mode, wait 10s and untick Airplane mode
and I also did fron desperation point 4.)
4. activate Siri and say: "let my SIM card work!"
and Since did these steps, I had no Invalid Sim!!:))
at least 24 hours no problems (knock-knock)
Yet another one here, been having "Invalid sim" since last monday 2- 3 times a day....
However I have been developing on this phone all weekend (plugged in via USB to my mac mini) - no errors for a good 14 hours on Saturday, unplugged it at 2am and went to bed.
when I checked it at 8am guess what? yeah "Invalid sim"
Its been plugged in again all day (15 hours) and no errors - I would be willing to put money on an "invalid sim" message when I wake in the morning after it has been unplugged.
Not sure what this really means, but I am guessing something around voltage drop or something when the phone is not plugged in due to battery discharge or something?
Anyone else get sim errors whilst charging overnight or does this just seem to be whilst running off the battery for everyone?