[GUIDE] Change to ANY G300/U8815/U8818 ROM via Boot loader version bypass [HACK]

[Guest elperroderoke]

2 possible causes either you haven't restored your imei as this removes chinese splash or

I think what ever splash screen you have when you make imei backup is replaced when you restore > so if you make a imei backup on b926 chinese version your restore chinese splash screens

You are right. I tried to go back from ICS to GB but just using CWM backup (not .zip) directly. It worked but instead IMEI=0, mine was just "Unknow". I restored my IMEI backup done in GB before update, and once rebooted the logo was changed (Yoigo Spain) even the IMEI wasn't restored (still "unknow"). Then I went back to ICS using the CWM backup, the boot image still Yoigo and the IMEI was there without need to restore.

Regards.

Edited July 9, 2012 by elperroderoke

[Guest Dazzozo]

That's because of the new baseband. Everything should work if you flash a B8xx ROM to B926 other than the mobile network (and vice versa for a B926 ROM flashed to B8xx).

[Guest elperroderoke]

I knew that to go back to GB I needed to flash the update.app, but I do not really need to do that (by now), just playing if the boot image was changed or not. By now I do not need or want to trick the bootloader, but now I have a question in mind:

What happen if once you have downgraded and fix the Imei, you reflash the same update.app (B882, for instance). Will this rewrite the boot loader with a new one, so you do not have to "trik" again to change Rom?

Regards.

Edited July 10, 2012 by elperroderoke

[Guest Gary_J_Wright]

I knew that to go back to GB I needed to flash the update.app, but I do not really need to do that (by now), just playing if the boot image was changed or not. By now I do not need or want to trick the bootloader, but now I have a question in mind:

What happen if once you have downgraded and fix the Imei, you reflash the same update.app (B882, for instance). Will this rewrite the boot loader with a new one, so you do not have to "trik" again to change Rom?

Regards.

no once you have ics bootloader its for good, but it wont hurt to try flash update.app(b882) again but i think it will fail

if at b926 when a newer rom (i.e b928 ) comes out no more need to bypass bootloader version i.d i hope.

Edited July 10, 2012 by Gary_J_Wright

[Guest Gary_J_Wright]

I knew that to go back to GB I needed to flash the update.app, but I do not really need to do that (by now), just playing if the boot image was changed or not. By now I do not need or want to trick the bootloader, but now I have a question in mind:

What happen if once you have downgraded and fix the Imei, you reflash the same update.app (B882, for instance). Will this rewrite the boot loader with a new one, so you do not have to "trik" again to change Rom?

Regards.

cwm should not be used with this method at all..... its fine to use before or after to make back up (only to be used with cwm) , but cant be used with the downgrade/upgrade method to restore anything

also cwm will only work ics to ics or gb to gb

not gb to ics or ics to gb

[Guest Dazzozo]

also cwm will only work ics to ics or gb to gb

not gb to ics or ics to gb

Wrong, CM9. ;)

[Guest elperroderoke]

no once you have ics bootloader its for good, but it wont hurt to try flash update.app(b882) again but i think it will fail

if at b926 when a newer rom (i.e b928 ) comes out no more need to bypass bootloader version i.d i hope.

I'm more or less understanding how it works (coming from Motorola Defy+, so diferent way).

Not knowing if an incoming realase will "repair" the boot loader, is the reason I won´t try unless it would be necessary, and right now I don´t see the point to go back to GB unless I have to sent the phone to be repaired on warranty, and even do, by the time maybe there will be an official Yoigo Spain ICS to be flashed (I assume everybody hope or think it would be posible the update from Unicom ICS just flashing the update.app)

Thank you for all the explanations.

Regards.

[Guest Gary_J_Wright]

Wrong, CM9. ;)

l

lol ok cm9 i meant official huawei ..... :P

[Guest apopberz]

I screwed up the ordering on this I think, What I've done because the official chinese ICS 4.0.3 install wouldn't work using the dload method I used this to backup and change my IMEI. Then I flashed a custom ICS rom *before* restoring the IMEI (but after getting root and reinstalling clockwork). Now i've restored my IMEI in the custom rom and it shows up fine in the settings or when I dial *#06# but I can't get any carrier signal (every now and then i get a 2g signal for a minute and it drops, weird).

I'm going to dload the offical update again and try restore the IMEI in there and hope that fixes it - any better suggestions?

[Guest Hans Gruber]

Are you on O2? Sounds like the problems they're having right now

[Guest apopberz]

Are you on O2? Sounds like the problems they're having right now

No Vodafone AU - I've got another handset here and my SIM is fine in that one, I've definitely messed up the radio/baseband on this G300 somewhere during this process

I don't seem to be able to undo whatever damage it is I've done here. I just put the stock gingerbread rom back on, changed the IMEI to one from the zip on this thread, then ran the official ICS update again. Then restored my original IMEI (after having used unlockbootloader.exe to root again)

Now I'm official ICS with my original IMEI back, root is working and I can verify the IMEI in the settings or using *#06# but still have no signal with a working SIM

Edit: I fixed this by flashing the official ICS, restoreing the IMEI then rebooting and allowing the cache to wipe etc. Scared to flash another custom ICS now but it's worth the risk so here I go...

Edited July 12, 2012 by apopberz

[Guest Pondlife]

Edit: I fixed this by flashing the official ICS, restoreing the IMEI then rebooting and allowing the cache to wipe etc. Scared to flash another custom ICS now but it's worth the risk so here I go...

So it's fixed? Or have I read that out of context?

[Guest Gary_J_Wright]

No Vodafone AU - I've got another handset here and my SIM is fine in that one, I've definitely messed up the radio/baseband on this G300 somewhere during this process

I don't seem to be able to undo whatever damage it is I've done here. I just put the stock gingerbread rom back on, changed the IMEI to one from the zip on this thread, then ran the official ICS update again. Then restored my original IMEI (after having used unlockbootloader.exe to root again)

Now I'm official ICS with my original IMEI back, root is working and I can verify the IMEI in the settings or using *#06# but still have no signal with a working SIM

Edit: I fixed this by flashing the official ICS, restoreing the IMEI then rebooting and allowing the cache to wipe etc. Scared to flash another custom ICS now but it's worth the risk so here I go...

As corrected by Dazzozo. you somehow have the wrong baseband / firmware @ a guess

The original update.app is ALWAYS official ICS we cant alter the update.app, This is B926 based with ICS basebands / firmware

Next flashable zips (CWM)

There are Two types of ICS modified ROM versions those that have ICS basebands, B926 based. they will come as a zip

some like cm9 and ligux are ICS modded ROM versions made to run on GB basebands /firmware again a zip

Edited July 12, 2012 by Gary_J_Wright

[Guest Dazzozo]

The partitions have absolutely nothing to do with the operating system that runs on it. We could get the old B8xx Gingerbread ROMs running on B926 if we were so bothered.

The key difference is the radio firmware change. There are two basebands, and two sets of firmware. A ROM with the firmware for the other baseband will result in you having no mobile network.

If your modified ICS is built for B8xx with B8xx firmware, RIL won't work on your B926 device, and vice versa.

"ICS partition layouts" is a bit redundant, the only thing that really changed in B926 was the system partition becoming ext4, which has nothing to do with radio problems.

[Guest Gary_J_Wright]

The partitions have absolutely nothing to do with the operating system that runs on it. We could get the old B8xx Gingerbread ROMs running on B926 if we were so bothered.

The key difference is the radio firmware change. There are two basebands, and two sets of firmware. A ROM with the firmware for the other baseband will result in you having no mobile network.

If your modified ICS is built for B8xx with B8xx firmware, RIL won't work on your B926 device, and vice versa.

"ICS partition layouts" is a bit redundant, the only thing that really changed in B926 was the system partition becoming ext4, which has nothing to do with radio problems.

cool think we need a guide of what works and how (Like the gen1 / gen2 blade) etc Really could do with a F A Q

[Guest apopberz]

So it's fixed? Or have I read that out of context?

That's correct. I had to do this to fix it:

1) Install stock gingerbread

2) Flash this downgrade (false IMEI)

3) Install official chinese ICS update again

4) Root again (unlockbootloader.exe)

5) Restore my IMEI *before* changing roms to a custom ICS rom

So basically repeating the whole process detailed here again. I tried restoring my IMEI while having numerous custom roms (both gingerbread and ICS) and none allowed me to get a carrier connection. I would suggest adding to the guide the original IMEI should be restored as soon as possible (ie. right after chinese ICS and root are done, possibly even before bootloader unlocking) as this one really f***ed me up and took me about ~8 hours of flashing to resolve.

[Guest Pondlife]

Nice one :)

Would never have thought that the imei restore wouldn't have worked on custom roms so definitely worthy of note.

[Guest milance022]

How to delete after downgrade ICS...China logo "3G WO"...I want Huawei logo :)

[Guest sonicaaaa]

Hi all, I am trying to upgrade Huawei official ICS ontop of Vodafone UK 882 without luck.

Have anyone been able to make it work? Any suggestion?

thank you

sonicaaaa

[Guest Pondlife]

First off don't

get the 885 ota update first for audio fixes

[Guest Gary_J_Wright]

Hi all, I am trying to upgrade Huawei official ICS ontop of Vodafone UK 882 without luck.

Have anyone been able to make it work? Any suggestion?

thank you

sonicaaaa

ota 885 then official ICS you DONT need this hack

Edited July 13, 2012 by Gary_J_Wright

[Guest maritimesbob]

I'm currently running ICS, have flashed the modaco ICS rom that Paul put together. Of course I went through the Chinese ICS update first then flashed the rom. I want to go back to GB, the guide in this thread would work for what I want to do?

Thanks.

[Guest Dazzozo]

ota 885 then official ICS you DONT need this hack

You can just go from 882 to 926...

[Guest Gary_J_Wright]

http://www.modaco.co...u8815-b927-rom/ use the update.app in the u8815 middle package this allow upgrage and down grade NO NEED to hack anymore Edited July 16, 2012 by Gary_J_Wright

[Guest FrankieADZ]

http://www.modaco.co...u8815-b927-rom/ use the update.app in the u8815 middle package this allow upgrage and down grade NO NEED to hack anymore

thats great news :D

I think you need to go another thread or something as you found this out :)