My brother and I purchased a studio 1536 at the same time with the same specs.  Mine works fine, but his every now and then will hung up at startup.  On the audio controls the volume up button is lit up and the laptop is making a loud beeping sound and it doesn't finish booting up.  I took the battery out and unscrewed the two little screws and took off the audio control bezel to see if anything was making contact and causing the error, but didn't notice anything.  Any help would be appreciated.  Thanks in advance.