NI PXI-2568 Relay Replacement

The NI PXI-2568 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 and replace a failed relay.

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 and table for relay locations.

   

   Channel Name	Relay Name	Channel Name	Relay Name
   CH0	K1	CH16	K17
   CH1	K2	CH17	K18
   CH2	K3	CH18	K19
   CH3	K4	CH19	K20
   CH4	K5	CH20	K21
   CH5	K6	CH21	K22
   CH6	K7	CH22	K23
   CH7	K8	CH23	K24
   CH8	K9	CH24	K25
   CH9	K10	CH25	K26
   CH10	K11	CH26	K27
   CH11	K12	CH27	K28
   CH12	K13	CH28	K29
   CH13	K14	CH29	K30
   CH14	K15	CH30	K31
   CH15	K16

3. Remove the four screws that secure the top-side lead cover. Retain the plastic spacers for reassembly.
   
   

   1 Screws 2 Top-side lead cover 3 Plastic spacers

Replace the Relay

Make sure you have the following:

• 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

Reassemble your module using the screws and the plastic spacers removed in Disassemble the Module, step 3.

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.