Syquest SQ555 Diagnostics - LED Error Reporting Table 
from the SQ555 OEM Technical Reference Manual, pg 5-3 
 
  # of LED blinks: 
  GREEN  RED/AMBER  ERROR DESCRIPTION 
 ------------------------------------- 
    1        1      EPROM failed checksum test 
    1        2      Internal uC RAM 
    1        3      External uC RAM 
    1        5      Seek error 
    1        6      Read error 
    1        7      Write error 
    2        1      Controller failure 
    2        2      Sequencer - Test 1 
    2        3      Sequencer - Test 2 
    2        4      R/W buffer address register - Test 1 
    2        5      R/W buffer address register - Test 2 
    2        6      R/W buffer RAM - Test 1 
    2        7      R/W buffer RAM - Test 2 
    3        1      PO test 
    3        2      uC port 
    3        3      P2 Test 
    4        1      Spindle motor failed to start 
    4        2      Spindle motor spins too slow 
    4        3      Spindle motor spins too fast 
    5        1      Power failure 
    5        2      Spindle speed abnormal or no servo 
    5        3      Unable to detect servos; possible defective cartridge 
    6        1      ADC calibration failure 
    6        2      ADC high current failure 
    6        3      ADC low current failure 
   off    flashing  Failed power-up sequence; possible defective cartridge 
 flashing   off     Unable to read; possible unformatted cartridge 
 
