NI PXI-2566 Relay Replacement

The NI PXI-2566 uses electromechanical armature relays.

Refer to the following table for information about ordering replacement relays.

Complete the following sets of steps to disassemble your module, replace a failed relay, and reassemble your module.

Disassemble the Module

1. Ground yourself using a grounding strap or a ground connected to your PXI chassis.

   Note  Properly grounding yourself prevents damage to your module from electrostatic discharge.

2. Locate the relay you want to replace. Refer to the following figure for relay locations.
   
   
3. To replace the CH4 through CH11 relays, refer to Replace the Relay.
   
   To replace all other relays, continue on to step 4.
4. Remove the screw and washer connecting the daughterboard and topside insulator to the CMI bracket.
   
   

   1 Daughterboard and topside insulator screws 2 Daughterboard and topside insulator washers 3 Daughterboard 4 Topside insulator 5 CMI bracket

5. Remove the topside insulator from the CMI bracket.
6. Reconnect the daughterboard to the CMI bracket using the screw and washer from step 4.

Replace the Relay

Before you begin, make sure you have the following items:

• Temperature-regulated soldering iron set to 300 °C
• 60/40 Lead/Tin solder (flux core)
• Solder wick
• Fine pick
• Isopropyl alcohol
• Cotton swabs

If you have a surface mount rework station, replace the relay as you would any other surface mount part. Otherwise, complete the following steps to replace the relay:

1. Use the soldering iron and solder wick to remove as much solder from the relay pads as possible. Do not leave the soldering iron on any lead for more than 5 seconds.

   Note  If it is necessary to reapply the soldering iron to the pad, allow the connection to cool completely before reapplying the soldering iron.

2. Apply heat to the pads one at a time, and use the pick to gently pry the relay pins from the pads. Make sure that the solder is molten before prying.

   Caution  Using excessive force on a soldered pad can result in lifting the PCB trace and ruining the daughterboard.

3. Remove the relay.
4. Clean the pads with isopropyl alcohol and cotton swabs.
5. Place the new relay on the PCB pads and solder.
6. Remove the excess flux with isopropyl alcohol and cotton swabs.

   Caution  Do not use flux remover to clean the board after relay replacement.

Reassemble the Module

1. Remove the screw and washer (from step 6) connecting the daughterboard to the CMI bracket.
2. Install the new topside insulator. Refer to the previous figure for the appropriate location.
3. Reconnect the daughterboard to the CMI bracket using the screw and washer from step 1. Torque the screw to 2.7 in.-lbs.

Tip  In NI-SWITCH 3.1 or later, you can use the Switch Soft Front panel to reset the relay count after you have replaced a failed relay.