[Galaxy S II Q&A, Help & Troubleshooting] golliver:
i know this is a resurrection, but don't see it has been resolved.

also found same/similar problem on another topic, but no resolution either.

couldn't find any resolution anywhere on the net, but possibly i'm just missing it (searching for wrong parameters?)

anyway, a friend of mine bought second-hand (third or even fourth hand to be precise) i9100 with 2.3.6 (stock KI3) on it. the guy who sold it to him said something like: "it works best on 2.3, on 4.x it's buggy".

it was working fine, but friend wanted newer OS, so we tried update. it didn't work, and i found out CSC was broken/missing. somehow i managed to repair it, and update was finally working, but was unable to find any for our location.

so next step was to find stock rom that would work on the device, and then i tried four different 4.1.2 stock roms from this topic.

after flashing it through odin, every one was acting fine, until couple of minutes after it started freezing or rebooting randomly.

then i tried flashing CWM, and flashing from sd card, but it was all the same.

wiping data, cache and dalvik cache, prior to flashing. wiping data after flashing...

nothing seemed to work.

GB works rock solid, ICS works better than JB, but stills it freezes or restarts randomly.

tried CM10, but all the same, except it works a bit faster then official JB. but who cares about speed if it freezes/restarts constantly?

back to who knows which build... freeze... samsung galaxy s2 - i9100... with yellow triangle... booting stopped.

so i decided to dig deeper, trying to find hungarian stock build (country we were told the phone came from) not being sure that KI3 is what the phone came actually with. i found 4.0.3, put it on SD card, wiped data, cache, flashed CWM, wiped data, cache, dalvik cache, flashed 4.0.3 from sd, wiped data, booted, entered location for updates - hungary. update found, hooray... downloading... installing... rebooting... working?

nope... it's worse than ever. trying to log onto google account. typing in email add.... freeze... switching phone on - freeze... thinking about... freeze.

i couldn't sit still. yellow triangle, all those reboots/freezes... at least i wanted that triangle gone, and without a JIG, there was only solution for me was to try triangle away. it wasn't available for download in my country from play store, so luckily xda was there. :)

somehow i managed to download it from the device, install it, click remove the triangle... it did it's magic, rebooted... and miracle happened!

no more freezes.

so i started torturing poor phone, benchmarking, playing games, listening to music.... it seemed stable for about an hour.

so i said to myself:

- it's possible that previous owners tried to upgrade it to newer firmware, and somehow screwed up the bootloader, which was fixed by this app? maybe that was all there was from the beginning? why not try putting 4.1.2?

and i did... took 4.1.2 spanish build from already mentioned page above, flashed it... and voila. working JB... torturing the phone... playing with it... hour passes, another hour...

friend wakes up... takes his phone in awe, starts playing with it.. we talk a bit... and then that look :eek: it just froze again!

from that moment on, the phone again starts restarting or freezing randomly...

and, yes, i still have no clue what could be the cause. it doesn't matter if wifi is on or off, if you're talking on the phone or not, bluetooth and gps are always off. only thing that he noticed is that it usually happens while he's using the phone (meaning: operating the digitizer or buttons). if he starts music playback and not touching buttons or screen, it will probably play for hours.

one more thing, but i doubt it would be the case. the battery in the phone is not original one that was shipped with it, but a quality replacement.

it doesn't feel as if the phone is overheating... so i don't know what else i could do with it.

for now, it's back to 2.3.6.

we both lost a week, torturing ourselves with this problem.

i don't know is there anything i could add more?

all suggestions are welcome. :)

cheers