Here is some info on set-up for these cubes.
http://md5live.com/asicminer-block-erupter-cube-setup/https://bitcointalk.org/index.php?topic=352658.0I agree that you need a PSU with dual 6-pin PCIe connectors that have sufficient 12V+ AMPs. From experience I think my BE ran fine on the normal speed with dual 20A rails on the PSU. The bitcointalk page referenced above says 28A/rail and that it jams the PSU to max in rush current when it first starts.
The other things that were must checks when I got mine were to ensure all the boards were seated correctly and that the fan was plugged in and spinning. The unit will immediately shut off if there is not a proper fan that meets the RPM rating that is expected. If you need a fan replacement at some point I think there is a MASCOOL 2200rpm fan has a high enough rpm.
Beyond that when I had mine once it was powered correctly with the fan it would allow IP connection to it to set up the mining information.
Good luck..