OHAUS TROOPER, Service Manual

Page: 14 / 70

2-2
CHAPTER 2 DIAGNOSIS
SYMPTOM
Scale will not turn on with
new batteries installed.
PROBABLE CAUSE
Incorrect battery installation.
Wiring harness defective or
battery clips connection bro-
ken.
Membrane Switch defective.
Main PC Board is defective.
REMEDY
Check position of batteries.
Remove the 6 screws from the bottom
cover of the scale, carefully remove the
platform, top cover and remove the flex-
ible cable from the Main PC Board.
Check dc voltage at pins 1 and 3 of
connector J6 on the Main PC Board. See
Figure 2-1. Voltage should read ap-
proximately 9 Volts dc. If voltage is not
present at the connector, remove the bat-
teries and make a continuity test be-
tween each of the connectors in the bat-
tery box to connector J6, pins 1 and 3 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, trace wiring and resolder or re-
place wiring as necessary. If OK, pro-
ceed.
See Table 2-3.
If the scale fails to turn on with a new
Membrane Switch, the Main PC Board is
defective and should be replaced.
-> Repair Procedures 3.2.
TABLE 2-2 TROOPER SCALE - WILL NOT TURN ON USING BATTERIES.