[Galaxy S I9000 Q&A, Help & Troubleshooting] rocked_out:
I have a Bell GT-I9000m that I've unlocked to use it on Rogers network.

At first, I did have problems. Didn't have a phone for a day, cause i installed an app called battery percentage something to my unrooted I9000m that soft bricked my phone. Then I really started getting into rooting. My warrenty was over and already using the phone with another wireless provider.

I still don't completely understand how all things works but I have got around. Tried many ROMs.

And I after using custom rom, I have installed previous stock rom(such as a previous froyo rom) then successfully able to update with Kies (only 1 time though, cannot remember which stock rom ive used). Anyways, it is possible to go back to exact stock state you've previsously had after installing a custom rom.

What i do:

1. Look for a custom rom that i like (such as CM7.1, darky rom, simplicity) in "Galaxy S I9000 Android Development" section. There should be a stick that has the list of ROMs or seperate posts with the latest ROMs. Download that ROM.

2. Read up on it. It will say which stock rom it is built from or say which stock rom you should install before installing the custom rom (i.e., 2.3.4jvr, 2.3.5jvt and such)

3. Find that stock rom. There are posts in the forum that says stock rom collection. Find the specified rom with Sbl(i.e., jvt, jvr)

4. Reboot ur phone into recovery mode (if u are coming from a stock rom, it will say 3e recovery). Do factory reset and clear cache (at this point, you should've backed up ur personal files already)

5. Reboot into Download mode(hold Home+volume down+power as you turn on the device). Run "Odin" on ur PC. If you unzip the stock rom file, it should contain 3 different files PDA, Phone, CSC.(Do not much understand this part, just following instruction. From what I understand PDA is like the OS?(like Windows?), Phone is the modem for like dialing, 3G connections and such? and CSC? no idea)

6. Put those 3 files accordingly into the odin and put "s1_odin_2010512.pit" file into the "PIT" section.(when you do this "Re-Partition" would automatically get cheched. Leave it as it is checked)

7. Connect your "I9000m" device with USB. PC will recognize your device. Click "Start". It will start doing stuff to your phone.

8. Find the Kernel that will root your device. Go to "Galaxy S I9000 Android Development". There's a sticky called "SGS - 2.3.4 Ginger Bread Custom Roms & Kernels). Scroll down and you will see the list of Kernels (i.e., CF-Root, Semaphore, Blockbuster and such. so far, I've only tried CF and semaphore, which worked fine for me). Click on one of them and find the one that matches the stock rom that you've install(stock jvr -> CF-Root-XX-OXA-JVR). Download that and unzip it.

9. Reboot your phone into Download moad again(hold Home+volume down+power as you turn on the device). Open "Odin" agian. This time only load the ".tar" file that was contained the Kernel that you've downloaded, nothing else. Connect your phone. Click on "Start". This will also do stuff to your phone. Again reboot into the "Recovery Mode". Do "Factory Reset" and "Clear Cache"

10. After Rebooting you will have "Superuser" app installed on your phone, if not download it from the marekt. Now, you are rooted.

11. For Semaphore and CF-Root, there's CWM or semaphore app, that let's me to reboot into CWM recovery mode (not the original 3e recovery).

12. Boot your phone Normally and Copy the Cumtom ROM file(.zip) onto your phone(has to be in the "internal SD", your "external SD" is not recognized in the recovery mode).

13. Boot into CWM recovery mode.

14. Go down using "volume down" button to "install zip from sdcard". Press "power" to select.

15. Again use "volume down" to "choose zip from sdcard". Press "Power" to select.

16. You will see the custom ROM file(.zip). Go down to the .zip file (i.e., "Simply_Honey_5.1_LightCWM.zip"). Press "Power". This will start doing stuff to your phone for awhile and boot after will take awhile as well.

17. Once you are successfully boot into the phone, it will ask you to set-up stuff(wifi, google account). Do all that. Now you are basically done.

18. My extra step. Reboot into "Download mode". Download the Stock "UGKG3" rom. Unzip it. Open "Odin". Load only "Phone" file into the odin from "UGKG3" ROM. Then click "Start"

*If you are gonna attempt to follow my steps, "DO IT OWN YOUR OWN RISK"

But from my experience, it is pretty safe procedure and you could go back to Samsung Stock state.

I've went through a lot of ROMs in a very short period of time. Had ROMs with random Reboot problem, roboot problem when playing games and cell signal pick-up problem. From my experience so far, ran into some bad lucks with the signal problem with the most recent JVT rom, even with stock. JVR was okay with the signal, but I flash the phone with "UGKG3" modem. Not entirely sure does it does affect the phone, just feel like doing it since it's for specifically i9000m. LOL.

Like the other guy said. If it works for I9000, it will most-likely work for I9000m.

Currently on "Simply Honey 5.1" 2.3.4jvs