NI SCXI-1169 Relay Replacement

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NI SCXI-1169 Relay Replacement

The NI SCXI-1169 uses electromechanical armature relays.

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

Relay Manufacturer Part Number
AXICOM (Tyco Electronics) IM42GR (3-1462037-1)

Relay Kit Part Number
National Instruments (10 relays) 779356-01

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 SCXI chassis.
    Note  Properly grounding yourself prevents damage to your module from electrostatic discharge.
  2. Remove the three rear screws from the back of the module.

    1 Rear screws
    2 Top cover
    3 Rear panel
  3. Carefully remove the top cover of the module using a flathead screwdriver.

  4. Remove the rear panel.

  5. Remove the hex standoffs from the front of the module.

    1 Hex standoffs
  6. Slide the relay assembly out of the enclosure.

    1 Relay assembly
    2 Enclosure
  7. Remove the four screws that secure the mezzanine board to the base board.

    1 Screws
    2 Mezzanine board
    3 Base board
  8. Separate the mezzanine board from the base board.

  9. Locate the relay you want to replace. Refer to the following figures and table for relay locations.

    Base Board

    Mezzanine Board


    Channel
    Name
    Relay
    Name
    Channel
    Name
    Relay
    Name
    Channel
    Name
    Relay
    Name
    Channel
    Name
    Relay
    Name
    CH0 K0 CH25 K25 CH50 K50 CH75 K75
    CH1 K1 CH26 K26 CH51 K51 CH76 K76
    CH2 K2 CH27 K27 CH52 K52 CH77 K77
    CH3 K3 CH28 K28 CH53 K53 CH78 K78
    CH4 K4 CH29 K29 CH54 K54 CH79 K79
    CH5 K5 CH30 K30 CH55 K55 CH80 K80
    CH6 K6 CH31 K31 CH56 K56 CH81 K81
    CH7 K7 CH32 K32 CH57 K57 CH82 K82
    CH8 K8 CH33 K33 CH58 K58 CH83 K83
    CH9 K9 CH34 K34 CH59 K59 CH84 K84
    CH10 K10 CH35 K35 CH60 K60 CH85 K85
    CH11 K11 CH36 K36 CH61 K61 CH86 K86
    CH12 K12 CH37 K37 CH62 K62 CH87 K87
    CH13 K13 CH38 K38 CH63 K63 CH88 K88
    CH14 K14 CH39 K39 CH64 K64 CH89 K89
    CH15 K15 CH40 K40 CH65 K65 CH90 K90
    CH16 K16 CH41 K41 CH66 K66 CH91 K91
    CH17 K17 CH42 K42 CH67 K67 CH92 K92
    CH18 K18 CH43 K43 CH68 K68 CH93 K93
    CH19 K19 CH44 K44 CH69 K69 CH94 K94
    CH20 K20 CH45 K45 CH70 K70 CH95 K95
    CH21 K21 CH46 K46 CH71 K71 CH96 K96
    CH22 K22 CH47 K47 CH72 K72 CH97 K97
    CH23 K23 CH48 K48 CH73 K73 CH98 K98
    CH24 K24 CH49 K49 CH74 K74 CH99 K99

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


Complete the Disassemble the Module steps in reverse order to reassemble your module.

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.