Publication 2364F-5.05 - March 1999
4-4
Testing Components
1. With power applied to the unit, check the LED indicators on the main
control board (see Figure 4.2).
Figure 4.2
LED Indicators
2. Set meter for DC voltage. Check the power supply to the main control
board by testing the voltage across the test points shown in Table 4.B.
Table 4.B: Power Supply Test Points–Main Control Board
Note: If a low voltage is seen, the ribbon cable (at J3) may need to be
connected/replaced, or the gate driver board may need to be tested (the
gate driver board supplies power for the main control board and
isolation board).
-15V
+ 15V
H ost
Fault
+ 5V
Enable
D S P
Fault
R 2R O K
S C A N port
O K
-15V
+ 15V
H ost
Fault
+ 5V
Enable
D S P
Fault
R 2R O K
S C A N port
O K
-15V
+ 15V
H ost
Fault
+ 5V
Enable
D S P
Fault
R 2R O K
S C A N port
O K
The LEDs should be illuminated as shown when
Normal Operation
the unit is enabled.
Check the fault queue if either of the fault LEDs
Fault LED(s) are Illuminated
Reinstall firmware if the host fault LED is flashing.
are illuminated (see chapter 3 to troubleshoot).
Check the wiring connections on the main
Power LEDs are not Illuminated (or are weak)
control board and test the gate driver board if
the power LEDs are not illuminated or are weak.
Test Points
Typical Voltage
TP4 to AGND
4.7 to 5.3V DC
TP20 to AGND
14.4 to 15.4V DC
TP26 to AGND
-14.4 to -15.4V DC