This applies to all updates... not just Gingerbread to ICS
Ice Cream Sandwich,
ICS, is not just an update... it is a whole new platform.
I have personally used a number of the ICS ROM's, LPS, LP7, LP8, LPD, LPF, LPG and LPI, and they are all stable and work well. So it's no good blaming the ICS platform I'm afraid.
When you upgrade to
ICS from
Gingerbread not only is the platform changed but all your app's and settings have to be reconfigured and integrated into the upgrade during the process. This is in an attempt by Samsung to retain everything on your phone so that you do not have to set it all up again after the change to
ICS.
If you stop and think about the millions of app's and the myriad of settings that this has to take into account then maybe you can understand why there are sometimes problems with SGSII phones after
ICS is installed.
Some of these problems are caused by app's that are not suitable for
ICS.
Remember, not all app's on the Play Store are ICS compatible yet. Other app's, that work on
Gingerbread, have to be updated for
ICS if possible, during the change to
ICS. No mean feat.
Also, the downloaded ICS update itself may have been corrupted. This can easily happen with OTA, (Over The Air), updates where an interruption has occurred with the download. This has also been reported by some who have used the Samsung PC suite, Kies. However, unless you do a
Factory Reset... you cannot be sure.
So, what can you do?
Well, I would strongly recommend a
Factory Reset after, or prior to, upgrading to
ICS.
Settings >
Back up and reset >
Factory data reset
Yes, I know, its a lot of hassle because you have your phone set up the way you like it on Gingerbread but it's a lot more hassle if things go wrong, as we can see from this forum. Besides, this is the very reason that Android include the
Factory Reset feature
Having said that, I always do a
Factory Reset and clean install so that there is no old setting or data from a previous ROM/firmware.
OK, I'm rooted, so it is easier for me with various tools, etc; that are available to rooted users. However, you are only going to be doing it once.
The object of the
Factory Reset is to return your phone's memory back to the out-of-the-box state with no user app's or data from
Gingerbread to cause problems. Make no mistake, if you are on
ICS, this does not revert you back to
Gingerbread.
These problems can manifest themselves in all sorts of ways... from non compatible app's continually running and causing high battery usage and over heating. Settings that are giving Forced Closes or very long screen lags. High RAM usage or screen freezes can all occur because the user app's or data have not, or can not, be integrated successfully into the
ICS framework automatically during the change to
ICS.
A
Factory Reset will not touch your
Internal* or
External SD cards. However, I would strongly suggest copying any files from the Internal memory to your computer, using a USB cable and Windows Explorer, for safe keeping.
* If you have any app's, settings or data stored on your Internal memory, you may also want to consider erasing this as well, after saving anything you wish to keep.
Settings >
Storage >
Erase USB storage.
You should also make sure that you are fully sync'd with your Google account so that Contacts and Calendar, etc; can be automatically restored after the
Factory Reset and your subsequent sign in to your Google account.
You can also, as a safeguard, save your Google Contacts by going into
Contacts >
Menu >
Import/Export >
Export to SD card.
Providing your app's are all sync'd with the
Play Store, they will start re-installing automatically, one-by-one after signing in with your Google account details, email/password. Your paid app's are still there as paid app's, so you do not lose them. The restore from the
Play Store will take some time and should be done via Wi-Fi as there will be a lot of data downloaded. You may find that you have to, "set-up", some of your app's again or that there are updates for a number of app's or that you will need to manually re-download some again. This is no bad thing as it was probably these very things that were causing problems in the first place.
If you have any passwords or Wi-Fi codes, etc; you should make a note of these before the
Factory Reset.
A handy app for backups, on un-rooted phones, is, "
MyBackup", and, "
MyBackup Pro", from the Play Store. However, be warned, you may well be restoring the very app's and settings that caused the problem to begin with. A safer method is to do a fresh install and set-up of each app.
This post by
Russell NG illustrates the steps that are taken. See,
here.
As I said, this may seem a lot of hassle but the alternatives are:-
1. Put up with your phone the way that it is on ICS.
2. Take it to a Samsung Service Point and get them to re-flash it for you... in which case you will lose everything anyway.
3. Re-install your old Gingerbread firmware using Odin and lose everything.
The choice, as they say... is yours.