Daktronics AB-1600-1.5,2.5 - Manual (Page 48)

4-6 Maintenance & Troubleshooting
The three critical parts of the ventilation system are the filters, the fans and the lenses. On the
bottom of the cabinet are a number of air filters, and above each air filter, within the cabinet, is a
fan. The fans draw cooler air from outside the display through the filters and into the display. This
incoming air forces warm air, already in the cabinet, out through the lenses on the face of the
display. Each lens has an exhaust port near the top to allow for airflow. Before the air exists
through the lenses, it passes past the lamps, cooling them in the process. This maximizes the life
of the lamps. Figure 45 illustrates this ventilation process.
To protect this display from heat-related damage, numerous button thermostats are in the cabinet,
usually mounted on the transformer mounting bolts. There is one thermostat for each fan in the
display. When the internal cabinet temperature climbs too high, one or more thermostats will
open. What happens next depends on whether this display is a Venus 1500 or Venus 4600 system.
If this is a Venus 1500 system, the master-echo board in the fan control enclosure of the master
display will sense the open thermostat. It will then send an alert to the Venus 1500 controller,
which will blank the display.
When the internal cabinet temperature drops to acceptable levels, the affected thermostats will
close and the display controller (serial line interface or Venus 1500 controller) will return the
display to operational status.
When the internal cabinet temperature drops to acceptable levels, the display controller (serial line
interface or Venus 1500 controller) will return the display to operational status.
The master-echo board, used on Venus 1500 systems, and the serial line interface board, used on
Venus 4600 systems, have LEDs on them to indicate which thermostats are closed. This is useful
information when troubleshooting. Refer to Master-Echo Board for master-echo board
information and Additional Venus 4600 System Components (Serial Line Interface) for serial
line interface board information.
In addition, the display controllers in 1600 series small matrix displays will turn off power to the
fans if they sense the display has been blank for 30 minutes. This action is completed through the
relay in the fan control enclosure. This extends the life of both the fans and the filters. The display
controller will start the fans automatically when the display is in use.
4.3 Servicing of Display Components
Reference Drawings:
Line Receiver Settings .......................................................................... Drawing A-110966
Line Receiver Settings .......................................................................... Drawing A-117756
Figure 45: Cabinet and Lens Airflow