quick question, I am on AOKP and franco kernel now, planning to root back to stock to get OTA jellybean update.

Will flashing yakju factory image 4.0.4 from developers.google allow me to do that?

Also, I once read that usually ROM comes with its own Kernel right? thats why we flash kernel after custom rom. so does the stock rom comes with stock kernel?

Well, I had a series of bad experience with the phone, not sure what caused it though.

I was jogging with the phone with earphones plugged in using the nike app, and suddenly it crashed (screen hangs and the music playing keeps reloop). I wrapped the phone in a ziploc bag to ensure that no moisture can go into the phone, and i double checked the ziploc bag later to find that no sign of moisture ever entered the bag.

So back to the phone, once it crashed, i had to pull battery to shut it off. After that, my device will boot to show that I have 0% battery and shut down right after that. After several tries, it wouldn't even boot pass the google screen. But i noticed that whenever i slot the battery in, the notification light will bilnk in red at various pace.

Tried rebooting alot of times, then tried boot into recovery mode and wipe data and tried again. Finally it boots and I managed to make it work again. But another problem still entrails. The phone thinks that my earphone is perpetually plugged in. Therefore all my media sounds do not work - eg. phone call can only work via loudspeaker, music player don't play, youtube don't play, notification sounds do work though. Those sounds that do not work will come through when i plug in my headphones though.

So i did a series of reset bla bla bla and finally it worked again. Then i started to notice that the battery life of the phone became worse. Initially i was able to get through a day without any problem at all, with at least 20% battery left. Now, my phone will become dead by 3-4pm. Tried recalibrating the battery, improved a lil bit. so i suspect is the kernel's fault - so thats why I want to flash it back to stock kernel and hope for the best.

Oh and 1 more thing, my USB connection does not work (no response from any computer after plugged in) since the fiasco, until 2 days ago, when i plugged in the USB cord, the connection worked but it keeps connects and disconnect.

Well you see, since I had USB connection problems, I might have a problem unrooting it. Haha, so I am trying to get it work again, flash back to stock, unroot, then try my luck with warranty service.

Was using 'Galaxy Nexus Toolkit v6.0', and yes from xda.

Oh mine is SME set, btw how to check the warranty period again huh? i remember sending sms or something like that.

Are you sure SME don't mind if the phone is rooted?? if thats true then its a real relief man..

Hmm, you have any idea any service centre is doing it? w/o checking rooted or not.

Yea totally understand that. Thats why i was hoping to unroot it before sending them, just to make sure in case they blacklist me.

To get it back, I have to flash stock rom (does it matter which one?), and lock bootloader?

Haha good trick. BTW, do i have to bring the boxes and stuff there if I wanna claim warranty? or just the phone by itself?

Receipt too? I thought samsung goes by E-warranty? I only have my phone and charger with me right now. Still can work?