| TROUBLESHOOTING |
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| Observe all Safety Guidelines detailed throughout this manual |
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| PROBLEMS | POSSIBLE CAUSE | RECOMMENDED |
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| (SYMPTOMS) | COURSE OF ACTION |
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FUNCTION PROBLEMS
LOSS OF OUTPUT IN BOTH MODES OF OPERATION
(Constant and Variable Voltage Positions)
Test Alternator Rotor Voltage (80- 90 Volts DC) Lead #222 to #1
1.If rotor voltage present go to Step 9. If no rotor voltage go to Step 2.
2.Lightly sand slip rings and reseat brush- es.
3.Flash rotor fields.
a)Turn machine off.
b)Use a 12 to 24 volt battery.
c)Apply voltage for 15 seconds, negative lead to #1, positive lead to #222 at alter- nator terminal strip.
CAUTION: Wrong polarity may dam-
age diodes.
4.Jumper leads #75 to #222
5.Continuity check - (Note B Pg.
a)Remove rotor brushes.
b)Disconnect #212 and #214 from alterna- tor terminal strip.
c)Remove all leads from #1 and #2 on con- trol box terminal strip.
d)Remove both Control Boards.
e)Check continuity from #214 to #1 and #212 to #1 with the positive lead on #214 and #212. This should read about 27,000 ohms. If shorted, check
6.SCR Bridge
7.Three phase bridge rectifier check.
a)Remove leads from three phase bridge rectifier assembly and check diodes (D7 - D8 - D9 - D10 - D11 - D12) See Procedure
8.Alternator continuity check - (Note B Pg.
a)Disconnect lead #212 and #214 and check winding for continuity.
b)Remove one rotor brush, check continuity of rotor field.
NOTE: Checking resistance of rotor field may cancel residual magnetism in the rotor iron. Repeat Step 3, "Flash Rotor Fields".
9.If Rotor Voltage is present check voltage between lead #75 and Pin #227 at the rear of Control Board #2 connector. (Approximately 15 to 22 volts DC.)
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
