CSZ MICRO-TEMP LT 749 - Page 59

FIELD REPAIR/SERVICE MICRO-TEMP
®
LT, Model 749
OPERATION AND TECHNICAL MANUAL
Page 59 of 75
TROUBLESHOOTING GUIDE
OBSERVATION
POSSIBLE
PROBLEM
ACTION TO BE TAKEN
E. Press a button and
nothing happens.
Blue ribbon cable
disconnected from
control board.
Correct connection to the
control board. Refer to
Section (5-2.3).
Defective control panel.
Replace control panel.
Refer to Section (5-11).
F. Display will not
illuminate
White ribbon cable
connector between the
display board and control
board is disconnected or
was improperly
connected to the display
control board or control
board.
Correct white ribbon cable
connections between
control board and/or display
board. Refer to Section (5-
2.3) and Section (5-2.4).
Defective control panel
and/or display board.
Replace control panel
and/or display board. Refer
to Section (5-11).
G. Low Water Caution
light on.
Reservoir water level too
low.
Add more water to the
reservoir.
Water level sensor wire
has a loose connection
to control board.
Properly reconnect the wire
to the J3 position of the
control board.
Defective water level
sensor.
Replace water level sensor
wire. Refer to Section (5-
10).
Lack of conductivity in
reservoir.
Add two (2) ounces of
Propylene Glycol as
instructed in Section 4-2.2.
of this manual. This
procedure improves
conductivity of the water in
the reservoir allowing
improved low water
indicator function.