THIS IS THE TEXT FROM THE PHASER 7700 SERVICE MANUAL, HOWEVER, SEE MY COMMENTS AT THE END OF THE QUOTE.
11 06-372 ERROR 11 LASER UNIT POLYGON MOTOR FAILURE
If this failure reoccurs three times successively, an Engine NVRAM
value is set preventing further printer use until the Clear Tech Rep
Fault, Clear <09-380 ~ 09-383> is run.
Remove Rear Cover (RRP 1, on page 7-154).
Disconnect P400 (see figure page 2-46) and P401 (see figure page 2-46) on the Engine Control
Inspect both connectors to determine they are fully engaged as a unit. Re-engage, if necessary.
The two connectors can NOT properly seat into their socket(s)
unless they are both engaged as a unit. Ensure there is no
Carefully reinsert the plugs into their joint socket and FIRMLY seat them.
Replace the Laser Unit (RRP 38, on page 7-200).
Whenever the mounting screws for the Laser Unit have been
loosened, it is necessary to recalibrate the unit by performing the
RegiCon Adjustment Procedure beginning on page 4-124.
If the problem persists, replace the Engine Control Board (RRP 42, on page 7-206).
It has been my experience that 90% of the time the scanner motor (polygon motor) has gone bad. I have repaired many 7700 printers with this error by replacing the laser scanner. The part can be purchased at: http://www.lpscomputer.com/p-3060-1-116-1110-00-laser-unit.aspx