downgrade from ics - Galaxy S II Q&A, Help & Troubleshooting

Hey guys.
I have tried new ics. As it nice is also terrible with battery....
Is there any way to downgrade it and then flash o2 firmware I have? I did try to flash it but setup wizard was crashing after reboot and I was stuck on that.
Any help will be appricated

---

Make a full wipe and install any stock gingerbread rom with ODIN.

---

After downgrading did you factory reset? That may fix the setup error.
Sent from my GT-I9100 using xda premium

---

sxi200 said:
After downgrading did you factory reset? That may fix the setup error.
Sent from my GT-I9100 using xda premium
Click to expand...
Click to collapse
After downgrading I'm stuck on setup wizard so I have no option for factory reset.
Need to downgrade as 10h-12h battery is a joke.

---

wolverine5pl said:
After downgrading I'm stuck on setup wizard so I have no option for factory reset.
Need to downgrade as 10h-12h battery is a joke.
Click to expand...
Click to collapse
Sure you do. Reboot to recovery (power off, then hold Vol-Up + Home + Power), and wipe data.

---

thanks guys, it helped but.... kies is saying its not supported any more now. I know for fact firmware I uploaded should be ok, but maybe is cause of root I did with ics?

---

wolverine5pl said:
thanks guys, it helped but.... kies is saying its not supported any more now. I know for fact firmware I uploaded should be ok, but maybe is cause of root I did with ics?
Click to expand...
Click to collapse
Kies will only show a firmware if all the codes match once you mess you change them .
Go to branded providers roms post in dev section download O2 rom .
jje

---

wolverine5pl said:
thanks guys, it helped but.... kies is saying its not supported any more now. I know for fact firmware I uploaded should be ok, but maybe is cause of root I did with ics?
Click to expand...
Click to collapse
I'm assuming the latest official ROM for your phone and network is Gingerbread.
Download and install Fus Downloader
Using Fus Downloader, get the gingerbread firmware for your exact phone (make sure product code, PDA, CSC and Phone match your phone)
Flash it with ODIN.
Once you phone has started, go to Settings -> Privacy -> Factory data reset.
Once that's done and your phone has booted again, flash the same ROM again.
Kies should now recognise your phone.
I had the same problem and this worked for me. What phone do you have? (country and network)

---

i have samsung galaxy s2 i9100 Uk O2.
im gonna try fus downloader, never heard of it before. big thanks guy for all help

---

beggin said:
I'm assuming the latest official ROM for your phone and network is Gingerbread.
Download and install Fus Downloader
Using Fus Downloader, get the gingerbread firmware for your exact phone (make sure product code, PDA, CSC and Phone match your phone)
Flash it with ODIN.
Once you phone has started, go to Settings -> Privacy -> Factory data reset.
Once that's done and your phone has booted again, flash the same ROM again.
Kies should now recognise your phone.
I had the same problem and this worked for me. What phone do you have? (country and network)
Click to expand...
Click to collapse
beggin You are the man. it worked, big thanks

---

Concerning the battery - i have stumbled upon this problem also.
Everything went away after few cycles discharging and charging. Now it is approx 20 % better than on GB.
Just be patient. Give it some time.
Rgds
Wysłane z mojego GT-I9100 za pomocą Tapatalk

---

beggin said:
I'm assuming the latest official ROM for your phone and network is Gingerbread.
Download and install
Using Fus Downloader, get the gingerbread firmware for your exact phone (make sure product code, PDA, CSC and Phone match your phone)
Flash it with ODIN.
Once you phone has started, go to Settings -> Privacy -> Factory data reset.
Once that's done and your phone has booted again, flash the same ROM again.
Kies should now recognise your phone.
I had the same problem and this worked for me. What phone do you have? (country and network)
Click to expand...
Click to collapse
Does this work for unbranded phones? I have a Unbranded UK GT-I9100. What region would i choose since they all have a network preference listed next to them?

---

nrz04 said:
Does this work for unbranded phones? I have a Unbranded UK GT-I9100. What region would i choose since they all have a network preference listed next to them?
Click to expand...
Click to collapse
Yes. Choose this.
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}

---

beggin said:
Yes. Choose this.
Click to expand...
Click to collapse
Just tried that...no firmware info retrieved for given data is what i get

---

I just had a look on fus downloader it appears to be called United kingdom (carphone Warehouse) I have just downloaded so I know it works

---

stubradley1 said:
I just had a look on fus downloader it appears to be called United kingdom (carphone Warehouse) I have just downloaded so I know it works
Click to expand...
Click to collapse
That's the wrong one. There's another one as shown in the picture above for Unbranded SGS2...it's not grouped with the other United Kingdom ones.

---

Strange that one is not on my fus downloader I get the europe GT-I9100LKAXEU
which gives the same details?? Fus 2.1??

---

If you do decide to go back to an ICS rom try Criskelo Servan Team ICS V5 works great. I get @ around 36hrs of battery using very often during the 36hr period having wifi & GPS on constantly. Using Facebook, YouTube alot.
Sent from my GT-I9100 using XDA