Replace the Relay

Make sure you have the following items:
  • Temperature-regulated soldering iron set to 316 °C (600 °F) for lead solder rework or 371 °C (700 °F) for lead-free solder rework
  • 63/37 Tin/Lead solder (flux core) for lead solder rework
  • 96.5/3.0/0.5 Tin/Silver/Copper solder (flux core) for lead-free solder rework
  • Solder wick
  • Fine pick
  • Isopropyl alcohol
  • Cotton swabs
Note NI recommends using lead-free solder for relay replacement on lead-free assemblies, and lead solder for relay replacement on lead assemblies.
Note Do not rework lead assemblies using a lead-free work station. Lead solder from the unit could contaminate the station.
Note If a lead-free assembly is reworked with lead solder, label the assembly to indicate this condition. This rework can prevent the same unit from being reworked later on a lead-free solder station, because it could contaminate the station.

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.
    Note Using excessive force on a soldered pad can result in lifting the PCB trace and ruining the board.
  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.
    Note Do not use flux remover to clean the board after relay replacement.