My T420s (2 months old) recently has been giving me a black screen after boot up (no "Thinkpad" image is displayed during boot up). System totally unresponsive -- I have to push on/off button multiple times. Subsequent boot up usually OK. Sometimes once I'm up and running, upon entering sleep mode, the machine will not wake up.
I have adjusted power management setting and and up-to-date on all drives. HELP!!!