New phones don't like old SIM cards, especially smartphones, although there are exceptions.
So, if you're using an old SIM and a new phone you may experience some problems (like phone freezes or loss of coverage, you cannot send SMS, cannot call anyone, restarts by it self etc.) then you need to go and visit your service provider (operator) to give you a new SIM. New version is SUPER SIM, ca. 250 contacts, multiple numbers under one contact name. Depending on your service provider (operator) they will change it with or without any cost. If that doesn't solve your problems than it's time to send your phone to authorized service.
For those exceptions it is still recommended to change them as they can later cause some difficulties and you could lose contacts and messages,
Also, take note that memory cards can make similar problems.
TIP OF THE DAY: Always keep your contacts saved on a SIM card and in phone memory!
Most of the new phones can even backup your contacts to memory card (its saved in .vcf file which most phone brands support nowdays) or save them to your computer!
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Some of the modern phones tend to freeze from time to time so it's a good thing to know what to do in that kind of situation. Usually you remove the battery and put it back in, but what about phones that don't have a user replaceable battery?
Well, it's quite simple, usually there is an option in settings menu that allows you to reset your phone to factory settings, but if you cannot turn your phone on, there is a combination of button presses that will do it!
REMEMBER: Use hard reset only as your last choice!!!
iPhone1.Press and hold the Home button (big circle under the screen) and the Sleep/Wake button(on top of the iPhone) at the same time.
2.Continue holding both buttons until device shuts down and begins to restart( ignore the Slide-to-power-off)
3.Let go of the buttons when you see silver Aplle logo.
4. It takes quite a while until device loads from the logo to home screen.
There is a possibility that you'll lose all of your user data (apps, contacts, messages, pictures, videos...)
Nokia N8-00
1.Turn off your phone.2.Press and hold these buttons at the same time: Volume down+Camera key+Menu key and then press power button until your phone shakes.
3.Wait until you see Nokia logo.
By doing hard reset on Nokia please have in mind that you'll lose all your user data!
(For all Nokia S60 devices you can enter a code (like you're gonna call somebody): *#7370# - this will also hard reset your Nokia.)
HTC
1.Turn off your phone2.Hold Volume down
3. Press and hold Power button until phone turns on
4.On the shown menu choose "Clear storage" by pressing Volume down
5. Press and release Power button to choose your selection
6.Now press Volume up for YES or Volume down for NO.
Again, ALL data will be lost!
Sony Ericsson Xperia (x10, x10 mini, x10 mini pro)
1. Turn off your phone2.Press and hold Home button (middle one)+Power Button for 5 seconds.
3.Release buttons when phone shakes.
4.Phone will turn on.
Hard reseting your phone will erase all user data!
If these tricks don't work on your phones than you have to send them to you're service for repairs!
TIP OF THE DAY: Back up your entire phone data (contacts, messages, e-mail, pictures, videos...) on your computer on a monthly basis! This way you will always be safe if something goes wrong with your phone.
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