Daktronics AF-3700-20 RGB - Manual (Page 37)

6.2 Ventilation System/ Fans
Frequency of Inspection
Figure 39: Air Exhaust
in Smaller Displays
In displays smaller than 64 pixels high, ventilation fans are located
along the bottom of the display. The fans pull air into the cabinet
from the lower vent, exhausting air out the top vent (Figure 39).
Displays 64 pixels high and larger have fans mounted on the back of
the display, pulling air from the front vents and out through hoods
(Figure 40). Sectional displays have fans in both top and bottom
sections. Air is pulled in either top or bottom vent and out the back.
Fans should be checked every time the display is opened or at a
minimum of once per year. Check more often if the display is located
in a dusty or harsh environment, such as along a gravel road.
Figure 40: Air Exhaust in
Larger Displays
Fan Blades
Check the fan blades for dirt and debris, cleaning them and the
inside of the display if necessary. Fan blades must be kept clean to
maintain fan efficiency and to ensure proper cooling. Spin the fan
blades with a pen or pencil to ensure that the bearings are free and
that the fan is still in balance.
Air Flow
To check the operation of the fans, open the display to expose the
thermostat. To locate the thermostat, refer to Figure 35 and Figure
36. Push the bypass button on the thermostat enclosure to
temporarily turn on the fans (Figure 42). If a fan does not rotate or
does not operate smoothly, replace it.
Make sure that the intake vents on the bottom front and the exhaust
vents on the top front of the display are not blocked and are free
of dust or other debris. Hold a piece of lightweight paper in front
of the top edge of the display to detect air movement through the
vents.
Figure 41: Air Exhaust in
Sectionals
Figure 42: Thermostat
Maintenance 27