[Galaxy S III Mini Q&A, Help & Troubleshooting] rlthomasgames:
Hello I really hope someone has a good solution for my problem (FIXED NOW - read whole post if interested), I have attempted quite a few supposed solutions that i found and always seem to run into the same problems, so I will try and explain as much as possible about my device and problem.

Firstly I have Samsung Galaxy SIII mini, I bought this from a carphone warehouse store in the UK under a o2 network contract but I believe it to not be network locked.

I then successfully rooted my phone with this image file ( https://mega.co.nz/#!qIsiEZIZ!L7rPSSTJ89-N3WrKs-i5vjYoW0lCIXMnkC5fGcnCg3o ) the other day using odin and by following this thread - http://xdaforums.com/showthread.php?t=2030282

Everything worked PERFECTLY and was extremely happy with the results I had now acquired super user control allowing me to use apps that require this privilege apps such as LCD Density changer (should be renamed "Samsung Bricker")

I stupidly used a LCD Density changer app, which i believe changed the density from 240 to 190.

Since this change the phone would not get past the very first load screen, meaning not the animated samsung logo but the simple galaxy s3 mini splash that is shown before. It still charged and I could still get to recovery mode, I dont think safe mode worked though. I could also still access it via adb on my PC.

So I followed a number of threads on how to use adb and shell to to edit the build.prop file to reset the density but even following numerous methods to make the /system folder and its contents rw (read writable) as opposed to ro (read only) and same goes for build.prop

I was never able to to push the build.prop file back into /system. Even when it seemed it had done it i would pull the build.prop file back again to check to see that there was no change whatsoever.

I also did not have anything like busybox installed to the best of my knowledge and seemed like a much more complex solution to any other thread.

I then wondered would the rom I previously installed contain the correct build.prop file in its system.img, I attempted to unpack these images to check but was unable to with numerous supposed tools available for windows ( I think ubuntu systems are the best for this ).

Just out of pure random stabbing in the dark I hit volume down + power + home once again. I suddenly saw the odin screen on my phone. "Hell to the Yeah" I thought to myself.

So I attempted to follow the thread (mentioned earlier) for the custom the rom using odin again (this was like the 3rd time i had tried to get the odin screen back, as you some times find the connection to the PC and phone to be very unstable at times, so due to this I had just assumed this wasn't going to work)

Now I see the odin screen perhaps, just perhaps the rom does include the build.prop file. So I started the process again and now even though I have wiped all my data as part of my trials to get the phone working again I now no longer have a brick rather than a phone! This process actually took place whilst I was in the middle or writing this post as I was at my wits end and desperately seeking help.

So I am posting this anyway with the hope it may at some point help some other unfortunate soul! MY PHONE NOW WORKS AGAIN! a few hours of my life gone but hopefully it'll save someone else these hours!

(word to the wise dont screw with the LCD Density unless you have a confirmed list of working density's)

Thanks for reading!

Best Wishes Rhys :D