Finding Crash Reason

[piyush]

I have a new Dell laptop with Linux Mint Debian edition installed .
I was watching a movie in Totem video player and I paused it and PC hanged it was not responding to Keyboard and Touchpad
after waiting for some time I pressed CTRL + ALT + PRTSC REISUBO . ( I've heard it's safer then hard reset)
and It should reboot but it powered off instead.
On restart I checked /var/log/syslog but It's overwhelming for me. Is there any GUI tool for finding out Crash reasons.
Plz help I want to know what was the cause of crash.