[Q] unable to enter download mode
My phone is an S3 i9300. Some weeks ago I installed an XXUGMK6 Android 4.3 version. At that time I was directed to an East European site (Russian?) which had one of the first releases. Everything have worked ok until I decided to try another ROM (Slimrom). I enabled USB debugging and tried to restart the phone in download mode (Power+Home+volume down buttons) to start the rooting process. I arrive at a screen saying:
A custom OS can cause critical problems in phone and installed applications.
If you want to download a custom OS, press the volume up key.
Otherwise, press the volume down key to cancel.
If I press the volume up key it apparantly starts downloading (text on screen: Downloading. Don't switch off your Phone). Nothing more happens even after almost 3 hours, and I have to force restart the phone.
I have tried to factory reset the phone, but it is still impossible to past the Warning!! screen.
Any suggestions on how to solve the problem are much appreciated.