NI PXI-2570 Relay Replacement

The NI PXI-2570 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	K0	CH20	K20
   CH1	K1	CH21	K21
   CH3	K2	CH22	K22
   CH4	K3	CH23	K23
   CH5	K4	CH24	K24
   CH6	K5	CH25	K25
   CH7	K6	CH26	K26
   CH8	K7	CH27	K27
   CH8	K8	CH28	K28
   CH9	K9	CH29	K29
   CH10	K10	CH30	K30
   CH11	K11	CH31	K31
   CH12	K12	CH32	K32
   CH13	K13	CH33	K33
   CH14	K14	CH34	K34
   CH15	K15	CH35	K35
   CH16	K16	CH36	K36
   CH17	K17	CH37	K37
   CH18	K18	CH38	K38
   CH19	K19	CH39	K39

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.