OHAUS EB SERIES, Service Manual

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CHAPTER 2 DIAGNOSIS
Ohaus Corporation www.ohaus.com 2-2 EB Series Scales Series Service Manual
TABLE 2-2. SCALE WILL NOT TURN ON USING BATTERY POWER
SYMPTOM PROBABLE CAUSE REMEDY
Scale will not turn on
using battery power. Battery discharged or
defective.
Wiring harness defective or
battery clips connection
broken.
Membrane Switch defective.
Main PC Board is defective.
Test the battery (Section 2.9). Replace
if necessary (Section 3.6).
Open the scale (Section 3.1). Check
voltage at battery contacts first. Check
DC voltage at the battery connector on
the Main PC Board. Voltage should
read approximately 6 Volts DC
minimum. If voltage is not present at
the connector, disconnect the leads
from the battery and make a continuity
test between the connectors on the
Harness to the connector on the Main
PC Board. Resistance should be 0
ohms for the red lead and 0 ohms for
the black lead. If an open condition
exists, replace wiring and connector as
necessary. If OK, proceed.
Test the Membrane Switch (Section
2.6). Replace if necessary
(Section 3.2).
If the scale fails to turn on with a new
Membrane Switch
, test the Main PC
Board (Section 2.8). If defective,
replace the Main PCB (Section 3.3.1).
After repair, proceed with Performance
Tests in Chapter 4.