Method: Downgrade from Gingerbread (XXJVK) to Froyo (XXJPY)

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Like many I installed the leaked version of Gingerbread on my Galaxy S when it first came out, but now Samsung have finally released Gingerbread in the UK, I would like to install the official release. But need to reinstall the official version of Froyo in order to do this via Kies.

I have had to spend quite a large amount of time looking for the process of doing this, as there seems to be conflicting information/methods out there. Also I understand Gingerbread has a new boot loader (the installed the version including the secondary boot loader) which also needs taking back to original, and I have also found that most of the guides out there always seem to leave a few questions unanswered

So after finding what appears to be the best and I believe the safest method, I thought I would post it on here for others.

Before I go into the steps on how i did this, I need to make a few points:

1) Any firmware installation carries risks. This is not approved by Samsung, and you do it entirely at your own risk....i’m no expert, I simply found a method that works for me. So if it all goes wrong, don’t come crying to me (however, after trying a different method previously, my phone would not boot, but I was able to re-flash with the leaked Gingerbread successfully).

2) Do not try this procedure if you are unable to get your Galaxy S into Recovery mode (Vol Up + Home + Power) and Download mode (Vol Down + Home + Power). A number of these phones have this issue, mine was one of them, there are guides online to fix this issue.

3) There seems to be a number of people who have issues with upgrades on Kies even when they haven’t messed with the firmware, so even if you cannot upgrade thru Kies, it doesn’t mean there has been a problem with Flashing the phone.

4) Backup your phone before flashing, as the phone will be wiped.

5) As far as I understand, this is only for the I9000 model and not for any of the other variants of this phone out there.

6) NEVER try to flash the phone without putting it into Download mode first, you will brick your phone.

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First of all you will need a Windows PC, USB Cable, 2 Downloads (below)....oh and ideally a Samsung Galaxy S

Download 1 (JPU)
http://hotfile.com/dl/99955459/dea69...XXJPU.rar.html
Password: samfirmware.com

Contents when extracted:
GT-I9000-CSC-MULTI-OXAJPU.tar.md5
I9000XXJPU-REV03-PDA-low-CL747761.tar.md5
MODEM_I9000XXJPU.tar.md5
s1_odin_20100512.pit
Odin3v1.3


Download 2 (JPY)
http://www.megaupload.com/?d=EWTHLRU6
No Password

Contents when extracted:
JPY_JPY_JPY.tar


The idea is to flash with XXJPU first to get the base version of Froyo which includes the SBL, then to Flash with JPY, this will allow you to use Kies for firmware updates (ensure Kies is completely closed before starting this).

1. Download and extract the above files.

2. Power off phone, remove sim and memory card, then start up in Download Mode and plug USB cable into phone (not PC).

3. Open Odin and select the following Files:

PIT: s1_odin_20100512.pit
PDA: I9000XXJPU-REV03-PDA-low-CL747761.tar.md5
PHONE: MODEM_I9000XXJPU.tar.md5
CSC: GT-I9000-CSC-MULTI-OXAJPU.tar.md5

Ensure the following options are ticked: Re-Partition, Auto Reboot & F.Reset Time

4. Plug the USB into the PC, after a few seconds it should displayan “Added” message in Odin, then click on the ‘Start’ button.

The JPU firmware will then be installed onto the phone, it will take a few minutes and the phone will reboot.

***Under no circumstances unplug the usb cable, press any buttons on the phone or generally do anything that could interrupt the process, until it has complete and the phone is full restarted***

Once this is complete, you are ready to flash the phone with the JPY version, very similar process, but please read as not all of Odin settings are the same.

5. With USB unplugged from PC, power off the phone and restart in Download mode.

6. Re-open Odin and select the following files:

PIT: s1_odin_20100512.pit
PDA: JPY_JPY_JPY.tar

Ensure the following options are Ticked: Auto Reboot & F.Reset Time (NEVER tick ‘Re-Partition’ when using a single firmware file for flashing as this could Brick your phone)

7. Plug the USB into the PC, after a few seconds it should displayan “Added” message in Odin, then click on the ‘Start’ button.

The Firmware will then be installed onto the phone, it will take a few minutes and the phone will reboot.

And thats it, you should now be able to upgrade the firmware via Kies....that’s assuming Kies is working correctly, and your carrier has released it, i’m with T-Mobile UK, but bought my phone through the Carphone warehouse, and was able to update immediately.

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I hope this has been helpful, if you have any queries, I will try to answer, but as I said I am no expert, i've simply spent alot of time looking for the best method

Just thought I should point out that xxjpy is a european version and is not carrier specific. So it shouldn't matter if your carrier has released gingerbread yet.

This method will allow kies to update your phone to the lastest european firmware.

Why the pain?

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No need to go through all this downgrading palava any more. Just use *spooffw and upgrade via kies as normal...easy peasy and no flashing required.

Search for "kies spoof"



*it fools kies into thinking you're on older firmware and offers you the upgrade to current fw

Don't need to tick "update bootloader"?

No, only tick the options stated in the guide.

Also be aware that you do not tick "Re-partition" on the second flash (JPY)

Sent from my GT-I9000 using Tapatalk

Thanks for the guide! I flashed it from a branded FW (was a backup) to stock and until now it's all pink and fuzzy!

Thank you, that's what i was looking for.

I never realized there was a written guide for this.
I just posted a video yesterday on how to debrand, unroot, and then update via kies.

Thus going from any custom kernel/rom theme etc.. to:
JPU, JPY then updating your version via KIES to JVO - good for warranty purposes.

thanks for this guide

Thanks for this guide. I was on JVO (samfirmware) and wanted to downgrade to get the official latest version installed later.

It didn't fully work for me but eventually got it working.

After having flashed from JPU to JPY Kies detected the phone (did not on JPU). However, it said there is no newer firmware version available.

So I flashed I9000XXJQ3_XXJPY_DBTJS2\PDA_JQ3.tar.md5 as PDA and I9000XXJQ3_XXJPY_DBTJS2\CSC_DBT_JS2.tar.md5 as CSC which I got from samfirmware (these were the versions I used to have on my SGS originally from Kies when I was still on 2.2.1).

*edit April 2012:*
had to downgrade again and went same procedure. However, couldn't remember whether I also flashed "phone". So this time I also added I9000XXJQ3_XXJPY_DBTJS2\PHONE_JPY.tar.md5 as PHONE in addition to the files I listed above as well as I ticked re-partition and added the same pit file I used on the first two flashes.
Afterwards, Kies detected the phone and offered the upgrade. Did that and now it has PDA: JVI, PHONE: JVO, CSC: JV2 (DBT)
*edit end*