SECTION X
10.0 FAULT FINDING
(SEE DRAWING B-2401-31)
The following section covers only simple faults that may occur. No attempt has been made in this
section to cover highly technical faults.
PROBLEM NO. 1: Unit does not turn on when power "OFF/ON" switch is depressed.
PROCEDURE &
EXPLANATION: If unit does not turn on at all, check battery voltage using a voltmeter. If
battery voltage is lower than four (4) volts because units has been
accidentally stored for a lengthy period with power on the voltage is too
low to illuminate display. Replace battery. (See Section VII Paragraph
7.5). If battery is okay, check power “ON/OFF” switch using an OHM
meter. Switch should normal show an open circuit. When depressed OHM
meter reading should be less than 2 Ohms. If switch is okay integrated
circuit chip is probably at fault. Return to factory or service center for
repair.
PROBLEM NO. 2: Unit stays on all the time, even though "OFF/ON" push-button is depressed.
PROCEDURE &
EXPLANATION: This symptom is usually indicative of a faulty power “OFF/ON” push-button
switch. Check the switch with an Ohmmeter as explained in Problem
No.1 above.
PROBLEM NO. 3: Unit turns on and off, however, when "Mode" switch is depressed system
does not switch to temperature it stays in Ullage/Interface mode always.
PROCEDURE &
EXPLANATION: Use OHM meter to make sure "Mode" switch is normally open and when
depressed is closed. If switch is faulty replace. If switch check out okay,
problem is probably an integrated circuit chip. Return to factory for repair.
PROBLEM NO. 4: Temperature readings are erroneous
PROCEDURE &
EXPLANATION: A.) When display is on does "Lo Bat" appear at upper left corner? If
so, replace battery with a new battery.
B.) If “Lo Bat” does not appear and display contrast in temperature
mode is not good and in particular the decimal point is very faint
or not visible, check battery voltage using voltmeter. If voltage
has fallen below 5.0 “Lo Bat” may not appear. Usually, under
these conditions the temperature readings will show extreme
errors.
C.) If battery checks okay, it is possible that the temperature sensor
in the sensing head may have been damaged by dropping unit or
unit may be out of calibration, due to severe exposure or abuse.
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