Mini-DIN to USB-Power
Let's assume it's Appletalk or Localtalk. I think that's a safe bet given that's it is a)old b)laser and c)8 pin din.

In all cases, only ground is available. Which is the same as most other serial port connection systems, USB aside.

Edit: Confirmed (after my browser crashed on that PDF!). That's a LocalTalk port. They come in various levels (more functions on the pins) but none of them carry power I'm afraid. See http://www.interfacebus.com/Apple_MiniDIN_PinOut.html