TX Matrix Plus Seven-Input 420-A Power Supply LEDs
The LEDs on the faceplate of each power supply (see Figure 1) indicate the status of the power supply. The PEM OK, FAULT, INPUT PRESENT, and PWR ON LEDs are located on the faceplate of the power supply. Additionally, the input power tray contains seven INPUT PRESENT LEDs, which are visible when the input power tray is removed from the power supply. A power supply failure also triggers the red alarm LED on the craft interface.
Figure 1: TX Matrix Plus Seven-Input 420-A Power Supply LEDs

Table 1 describes the seven-input 420-A power supply LEDs on the faceplate.
Table 1: TX Matrix Plus Seven-Input 420-A Power Supply LEDs
LED | Color | State | Description |
|---|---|---|---|
INPUT PRESENT—One per input | Green | On steadily | Input is receiving voltage. |
Red | On steadily | Input is reversed. | |
– | Off | Input voltage is not present. | |
PWR ON—One per input | Green | On steadily | Circuit breaker is powered on. |
– | Off | Circuit breaker is not powered on. The circuit breaker might have been turned off, the host subsystem detected a failure and turned off the circuit breaker, or the power supply is not receiving any input voltage. | |
PEM OK—One per power supply | Blue | On steadily | Power supply is functioning normally. |
– | Off | Power supply might be starting up or not receiving any input voltage. The circuit breakers might be off, or a fault has occurred. | |
FAULT—One per power supply | Yellow | On steadily | Power supply might be starting up, not properly installed, not receiving sufficient power, or not functioning properly. Inputs 0 through 4 might have failed. |
– | Off | No faults have been detected for the power supply, or the power supply is not receiving any input voltage. |
Table 1 describes the seven-input 420-A power supply LEDs (shown in Figure 2) that are visible on the input power tray after it has been removed from the power supply.
Figure 2: Seven-Input 420-A Power Supply LEDs

Table 2: TX Matrix Plus Seven-Input 420-A Power Supply LEDs on the Input Power Tray
LED | Color | State | Description |
|---|---|---|---|
INPUT PRESENT—One per input | Green | On steadily | Input is receiving voltage. |
Red | On steadily | Input is reversed. | |
– | Off | Input voltage is not present. |
