(9)   Remove   screws   (32)   which   secure   brackets (33  and  34)  to  chassis  (3)  and  remove  brackets. (10)   Remove   screws   (35)   which   secure   terminal board  (36)  to  chassis  (3)  and  remove  terminal  board. (11)   Remove   screws   (37)   which   secure   trans- former   (38)   to   chassis   (3)   and   remove   transformer. (12)   Remove   screws   (39)   which   secure   electronic component  assembly  (40)  to  bracket  (42)  and  remove electronic   component   assembly   and   spacers   (41). (13)   Remove   screws   (43)   which   secure   brackets (42)  to  chassis  (3)  and  remove  brackets. (14)   Remove   screws   (44)   which   secure   filter (45)  to  chassis  (3)  and  remove  filter. b.  Voltage  Regulator.  See  figure  8-16  to  disas- semble   the   voltage   regulator. c.   Voltage   Regulator   Printed   Circuit   Board   Assem- bly:   See   figure   8-17   to   disassemble   the   voltage   regu- lator  printed   circuit   board   assembly. d.  Electronic  Component  Assembly.  See   figure 8-13   to   disassemble   the   electronic   component assembly. 8-12.  Inspection  and  Testing, a..   Inspection. Proceed   as   follows: (1)   Inspect   the   complete   assembly   and   all   com- ponents  for  signs  of  physical  damage. (2)   Inspect   electrical   components   for   signs   of overheating. b.  Testing.  See  figure  1-8  and  proceed  as  follows: (1)  Disconnect  diodes  CR201  through  CR206 from   heat   sinks   and   test   each   diodes   per   paragraph 14-10. (2)  Refer  to  table  8-2.  Disconnect  one  side  of each   resistor,   and   use   ohmmeter   to   check   resistance. (3)  Check  A201  RFI  filter  by  disconnecting filter   leads   and   checking   resistance   across   terminals 1   and   1A,   and   across   terminals   2   and   2A.   Resist- ance  should  be  less  than  two  ohms. (4)  Check  SCR  (Q205)  as  follows: (a)  Disconnect  lead  from  terminal  1  of voltage   regulator   circuit   card   assembly. (b)  Set  ohmmeter  to  RI  scale.  Connect  meter positive  lead  to  stud  of  SCR  and  negative  lead  to  large terminal   of   SCR.   Ohmmeter   should   indicate   open   cir- cuit.  Reverse  leads. (c)  Short  small  terminal  (gate)  of  SCR  to ground.   Ohmmeter,   connected   as   in   (b),   should read  between  10  and  40  ohms. (5)   Check   voltage   regulator   and   electronic component   circuit   board   assemblies   as   follows: (a)   Interconnect   excitation   system   assembly to  test  setup  as  shown  in  figure  8-19. (b)  Adjust  variac  for  70  volt  ac  input  indi- cation   on   ac   voltmeter.   Dc   voltmeter   should   read approximately   25   volts. (c)   Increase   ac   input   to   80   volts.   Dc   volt- meter   should   increase   proportionally   and   read approximately   30   volts. (d)  Increase  ac  input  gradually.  At  approxi- mately  95  volts  input,  dc  voltmeter  should  drop  to zero   (indicating   zero   field   voltage   output).   If   dc   volt- age  does  not  drop  to  zero,  replace  both  the  electronic component   and   voltage   regulator   circuit   boards   and repeat   steps   (a),   (b),   (c),   and   (d). (6)  See  figure  1-8  and  check  the  50/60  Hz electronic   component   assembly   as   follows: (a)  Connect  one  end  of  a  1000  ohm  1/2  watt carbon  resistor  to  terminal  4. Table  8-2.  Excitation  Assembly  Resistor  Values Reference Mode I Sets Mode 11 Sets Designation (50/60  Hz)  (ohms)  (400  Hz)  (ohms) R201 220 220 - R202 2000 2000 R203 100 100 R204 3300 3300 R205 680 680 R206 100 100 R207 1000 1000 R208 1000 1000 R209 1000 1000 R210 2700 2700 R211 50000 50000 R212 10000 10000 R213 3000 3000 R214 5000 5000 Reference Mode I Sets Mode II Sets Designation (50/60  Hz)  (ohms)  (400  Hz)  (ohms) R215 150 150 R216 1000 1000 R217 1000 1000 R218 5100 5100 R219 15 6.8 R220 5000 5000 R221 30 30 R222 30 30 R223 30 30 R224 0.5 0.5 R225 300 300 R226 100 100 R227 120 120 Change 6 8-23