OHAUS TROOPER, Service Manual

Page: 13 / 70

2-1
CHAPTER 2 DIAGNOSIS
2. DIAGNOSIS
This section contains information needed to properly evaluate the reported problem and diagnose its cause.
2.1 SCALE SETUP AND EXAMINATION
Set up the scale according to the Instruction manual. Allow the scale to stabilize to room
temperature. Examine the scale for signs of corrosion or physical damage.
2.2 PRELIMINARY CHECKS
Power up the scale using the customer's ac adapter. In the case where the scale will not power up,
check the ac adapter. Observe and record the error codes and software revision. Record all menu
settings if possible as received.
2.3 TROUBLESHOOTING TABLES
Troubleshooting tables 2-1 through 2-14 identify actual types of problems that could be
encountered with the scale.
Trooper Scales are covered in Tables 2-1 through 2-7.
Trooper Count Scales are covered in Tables 2-8 through 2-14.
The troubleshooting tables refer to interconnection and wiring diagrams in this section to assist in locating
the problem.
SYMPTOM
Scale will not turn on with AC
adapter supplied
PROBABLE CAUSE
Adapter defective.
DC input connector at rear of
scale is defective.
Membrane Switch defective.
Main PC Board is defective.
REMEDY
Check the ac adapter voltage output.
The ac adapter output should measure
12-16 Volts dc. If voltage is low or
nonexistent, replace the ac adapter. If
OK, proceed.
Disconnect the ac adapter. Remove
the 6 screws from the bottom cover of
the scale, carefully remove the plat-
form, top cover and disconnect the
flexible cable from the Main PC Board.
See Figure 2-1.
Reconnect the ac adapter to the scale.
Check dc voltage at pins 1 and 4 of
connector J7 on the Main PC Board.
Should read between 12-16 Volts dc
(power off), 12-14 Volts dc (power
on). If voltage is not present, replace
the Main PC Board. If OK, proceed.
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 2-1 TROOPER SCALE - WILL NOT TURN ON WITH AC ADAPTER.