Urgent : fedora 21 on lenovo g505s installs but stuck @ bootup screen

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Hi there,

I wanted to install fedora 21 workstation and i did. the installation was done from a bootable USB and installation succesfully finished. Later when i boot system does get stuck @ startup after selecting to boot using any fedora modes.

Not even terminal mode boot is happening. system hanged up.

my laptop is powered with AMD apu and gpu. and so i tried to install in basic graphics mode even then the problem persists. So booted using live image and checked for log files in /var/log but in vain, all the log files are empty.

Can some please help me out here urgently.