OHAUS EC Series, Service Manual

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2-4
CHAPTER 2 DIAGNOSIS
TABLE 2-5 BALANCE READING INCORRECT OR UNSTABLE.
TABLE 2-6 CANNOT CALIBRATE THE SCALE.
SYMPTOM
Balance reads incorrectly.
Balance reading unstable.
PROBABLE CAUSE
Needs calibration.
Load Cell is damaged.
Main PC Board defective.
REMEDY
Perform Service Calibration in Appen-
dix B. If calibration fails, refer to Table
2-6.
Test the Load Cell, refer to Section 3.3.
If defective replace, see Section 4.4.
After repair, proceed with Performance
Tests in Section 3.6.
The Main PC Board should be tested in
accordance with Section 3.4. The Main
PC Board if defective should be re-
placed. See Repair Procedures 4.3.
After repair, proceed with performance
Tests in Section 3.6.
SYMPTOM
Scale can be turned on but will
not calibrate.
PROBABLE CAUSE
Incorrect weights.
Load cell assembly defec-
tive.
Main PC Board defective
REMEDY
Verify that proper weights are used.
Test the Load Cell, refer to Section 3.3. If
defective replace, see Section 4.4. After
repair, proceed with Performance Tests
in Section 3.6.
The Main PC Board should be tested in
accordance with Section 3.4. The Main
PC Board if defective should be replaced.
See Repair Procedures 4.3. After repair,
proceed with Performance Tests in Sec-
tion 3.6.