Shugart SA850 Service Manual page 54

Replace Head
Load Solenoid
Para. 2.4.6
END
NO
Check
Logic Level
at TP11
Check
Logic Level
at 3A Pin 3
Replace
Drive
PCB
HEAD LOAD INOPERATIVE
Check
Logic Level
at 5C Pin 3
Check Door
Close Switch
for Loose Wire
and Insure Closure
48
Check
1/0 Cable or
Controller
Replace
Door Switch
NO