Cabinet Service Procedures
2.3 Accessing the Electronic Components
1.The component shelf is accessed by removing two screws on each side of the unit (Fig. 1).
2.Lift and remove the sides, which exposes screws that hold the top in place (Fig. 2).
3.The components are annotated below (Fig. 3).
LON board
Cooling fans
LON filter
Fans:NOTE:areThespecificcoolingtofans regionsrest onofducts,the cabinetand cool
and ducted to direct specific regions of the
the air flow. cabinet.
Master
Display
Board
Master Control Board
LON filter
Power supply
Figure 3
Relay
All the components are readily removed. There are no replaceable components on the circuit boards.
2.4 Circuit Board LED Diagnostics
Master Control Board:
•HB LED is a heartbeat; should be flashing when in the normal
in- use mode. Flash rate is not | Fig. 4: Master Control Board LED's |
critical. |
|
•ACT LED similar to HB but flashes at a faster rate.
•OK LED toggles each time a valid communication packet is sent and received. Normally a very fast flicker.