Replacing a TX Matrix Plus Seven-Input 420-A Power Supply
- Removing a Seven-Input 420-A Power Supply
- Installing a Seven-Input 420-A Power Supply
- Powering On a Seven-Input 420-A Power Supply
Removing a Seven-Input 420-A Power Supply
The TX Matrix Plus router has two redundant, load-sharing DC power supplies. Each power supply is hot-insertable and hot-removable. When one power supply is powered off or removed, the other power supply automatically assumes the entire electrical load for the TX Matrix Plus router. The power supply weighs 35.5 lb (16.1 kg). The input power tray weighs 3.7 lb (1.7 kg).
To remove a seven-input 420-A power supply:
- Switch off the customer site circuit breakers to the power supply being removed.
- Make sure that the voltage across the DC power source cable leads is 0 V and that there is no chance that the cables might become active during the removal process. Verify that the INPUT PRESENT LEDs on the power supply faceplate are off.
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
- Switch the circuit breakers on the power supply
faceplate to the off position (O).

Note: After powering off a power supply, you must wait at least 60 seconds before turning it back on.
- Loosen the captive screws that secure the input power tray to the power supply.
- Grasp the metal handle of the input power tray and pull it down toward you.
- Remove the input power tray from the power supply.
Figure 1: Removing the Input Power Tray


Note: It is not necessary to remove the power cables from the input power tray when you are replacing the power supply.
- Twist the ejector handles on the upper corners of the faceplate counterclockwise to unseat the power supply.
- Grasp the handle on the power supply faceplate
and pull firmly. Slide it halfway out of the chassis (see Figure 2).
Figure 2: Removing the Input Power Tray and Power Supply

- Place one hand underneath the power supply to support it and slide it partly out of the chassis until you can reach the two handles located on each side of the power supply.
- Use the two handles on each side of the power supply to support it and slide the power supply completely out of the chassis.
![]() | Warning: Do not touch the power connectors on the rear of the power supply. They can contain dangerous voltages. |
![]() | Caution: Each seven-input 420-A power supply weighs approximately 35.5 lb (16.1 kg). Be prepared to support the full weight of the power supply as you remove it from the router. |
![]() | Caution: Do not leave a power supply slot empty for more than a short time while the router is operational. For proper airflow, the power supply must remain in the chassis or a blank panel must be used in an empty slot. |
Installing a Seven-Input 420-A Power Supply
Each seven-input 420-A power supply without the input power tray weighs approximately 35.5 lb (16.1 kg). The input power tray weighs3.7 lb (1.7 kg). To install a seven-input 420-A power supply:
- Switch off the customer site circuit breakers for the DC power cables connected to the input power tray being removed.
- Make sure that the voltage across the DC power source cable leads is 0 V and that there is no chance that the cables might become active during installation.
- Verify that the INPUT PRESENT LEDs on the power supply faceplate are off.
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
- Switch the circuit breakers on the power supply faceplate to the OFF position (O).
- Remove the input power tray from the replacement power supply. Store the input power tray.
- Using both hands, slide the power supply into the
chassis until you feel resistance (see Figure 3).
Figure 3: Installing a Seven-Input 420-A Power Supply

- Slide the power supply input tray into the new power supply.
- Push the metal handle of the input power tray up toward the power supply.
- Fasten the input power tray to the power supply using the two captive screws. Use a Phillips screwdriver.
- Twist the ejector handles at the upper corners of the power supply faceplate clockwise until they stop.
Powering On a Seven-Input 420-A Power Supply
To power on a seven-input 420-A power supply:
- Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
- Switch on the customer site circuit breakers to provide voltage to the DC power source cables.
- Verify that the INPUT PRESENT LEDs on the power supply faceplate are lit steadily green, indicating that the inputs are receiving power.
- Switch the circuit breakers on the power supply
to the ON position (|).

Note: After a power supply is powered on, it can take up to 60 seconds for status indicators—such as the LEDs on the power supply, the command output displays, and messages on the LCD display on the craft interface—to indicate that the power supply is functioning normally. Ignore error indicators that appear during the first 60 seconds.
- Verify that the PWR ON LEDs on the power supply faceplate are lit steadily. The PWR ON LEDs blink momentarily, then light steadily to indicate that the circuit breakers are on.
- Verify that the PEM OK LED on the power supply faceplate is lit steadily and that the FAULT LED is off, indicating that the power supply is correctly installed and is functioning properly.
![]() | Note: After powering on a power supply, wait at least 60 seconds before turning it off. If the system is completely powered off when you power on the power supply, the Routing Engine boots as the power supply completes its startup sequence. If the Routing Engine finishes booting and you need to power off the system again, see Powering Off the TX Matrix Plus Router. After powering off a power supply, wait at least 60 seconds before turning it back on. |


