mac pro won't sleep

[zachiel1]

I added a second optical driver for my mac pro 2010 8 core
since then i herring every few socond the the driver trying to reada disk the yellow light is blinking' also i noticed that the computer is not entrung to sleep mode
could you please help me about that
Thanks

 

[GGJstudios]

You may find some useful ideas here:

Mac OS X: Why your Mac might not sleep or stay in sleep mode
Determine why your Mac wakes up from sleep
One sleep problem caused by printers - solved ... and another