[Q]Problems with flashing custom ROMS - Galaxy S III Q&A, Help & Troubleshooting

Lately i'm experiencing problems with flashing custom roms (i.e. UltimaROM , Xperianze, whatever)
What i did is:
1: flash the latest CWM , touch and non -touch with Odin
2: download ROM of choice , copy to internal SD-card
3: reboot recovery, fact-reset, wipe cache + dalvik
4: flash rom ( with aroma installer )
5: boot phone
with booting it keeps hanging on the Samsung i9300 logo txt. It doesnt matter which rom i flash. it always keeps hanging.
I've tried alternative methods like flashing TWRP and do the same as above but again, no success. I also tried factory-reset after flash, cache wipe etc. no success.
The weirdest thing is: when i try to flash CM or MIUI ( current running MIUI ) , it works like a charm, but normal "custom" roms are not approved it seems.
does anyone have a suggestion for me what to do? or explain what i am doing wrong , or even better, can explain why CM-based ROMS work?

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Have you checked the MD5 of your downloaded ROMs when they are on your SD card? Format system, data and pre-load before flashing? Tried flashing an alternative kernel/radio before you boot the first time?
If only stock based ROMs are a problem then it maybe something that is unique to them, probably a direct hardware hit via the kernel.
Try returning completely to stock to test, flashing Samsung's vanilla EMB5 via Odin - including stock recovery and full wipe. If that doesn't work then you may have a hardware issue that CM or MIUI doesn't use.

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yeah good idea to return to stock and try all over again.
to your other questions: no i didnt flash another kernel after i flashed the custom rom. i've tried with several kernels which options were given to me in aroma installer ( boeffla, syah, stock )
md5: did that
format system and data: nope. kinda relied on the fact-reset + cache/dalvik
what do u mean with pre-load?

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if I were you I would format data & system again manually after the fac. reset thing, or even more clean use the mega wipe flashable zip to have a clean slate to start from (it will format anything but the ext. sd-card). Then flash the rom from your ext. sd-card and see how it goes.

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additional possibly helpful hints
hi there,
i'm not entirely sure if this will help you but generally speaking i came made a few observations about the fact that some people, mostly repeatingly the same users, encounter problems with their custom roms and/or flashing them, while others don't, albeit they are using the same devices.
i my selfe use 3 different devices, all rooted and running on pac 4.3, always lates nightly, as there are GT-N7100 - GT-I9100 - Nexus 4
not to the point
a) other than most other users i usually clean cache and dalvik cache as well before and after flashing the new rom and/or new nightly
and never encountrer any problems except those which everybody, using the same rom and nightly encounters.
b) whenever i flash an totally different rom and/or upgrade and/or downgrade to another level of android os, i.e. from 4.2.2 to 4.3, i perform
a clean install, including not only a factory reset, but as well a format sd-card, format cache and format system etc., again i cannot proof
which of these steps make a or the differnce but however, i never have problems others than thosw which everyone has with a version.
c) when using cusome kernels and due to the fact that some roms come with a kernel included, as well as with a custom recovery included,
it is strongly recommended not to forget to flas the kernel again after each flashing the new rom. one good example ist dorimanx kernel
for GT-I9100 which will not boot into recovery and reluctantly boot at all after a new flash of a pac nightly without reflashing the kernel.
d) try to fix permissions on reboot instead of doing it from recovery. one reason is that not every recovery has this option and further i
found that when fixing permissions before the first boot after flashing a new rom, there might be bootloops, albeit i cannot explain exactly
why that should, but however, sometimes it's better to be on the safe sid.
e) try to run whether the lastes version of custom recovery for your device, and or the use the included custom recovery of the rom or the
kernel. this again is one thing that can help to avoid some unexpected and hard to explain bootproblems and/or fc's etc.
hope that i could give you some new ideas how to avoid trouble while using custom roms and other hacks

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magnamentis said:
try to fix permissions on reboot instead of doing it from recovery. one reason is that not every recovery has this option and further i
found that when fixing permissions before the first boot after flashing a new rom, there might be bootloops, albeit i cannot explain exactly
Click to expand...
Click to collapse
Fix permissions was removed because its useless. All permissions are set when flashing by way of updater-script. Fix permissions via recovery "guesses" the permissions which causes issues...
If permissions need fixing, then the updater-script is poor which means you should probably avoid flashing it.
Sent from my GT-I9300 using Tapatalk 4

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rootSU said:
Fix permissions was removed because its useless. All permissions are set when flashing by way of updater-script. Fix permissions via recovery "guesses" the permissions which causes issues...
If permissions need fixing, then the updater-script is poor which means you should probably avoid flashing it.
Sent from my GT-I9300 using Tapatalk 4
Click to expand...
Click to collapse
thanks for the explanation which makes totally sense, so my feeling which i could not explain was right always better to learn exactly why than just guessing
no thanks button found in your post however, so i want to thank you this way.
regards