Install SIM cards

WARNING! Are you using consumer-grade SIM cards in a device that is subject to shock, vibration, or material expansion/contraction due to seasonal temperature variations? If so, these extreme conditions can lead to contact fretting and unexpected SIM card failure. Digi strongly recommends using industrial-grade SIMs instead of consumer-grade SIMs. Industrial-grade SIMs are designed for extreme environments and are constructed of heavier-gauge materials and extended-temperature electronic components.

To install SIM cards:

  1. On the TX40 front panel, use a screwdriver to remove the SIM slot cover.
  2. For high-vibration environments, SIM card contact fretting may cause unexpected SIM card failures. To help avoid this, apply a thin layer of dielectric grease to the SIM contacts. See Apply Dielectric Grease over SIM Contacts for instructions.
  1. Remove the SIM tray(s) from the TX40.
  2. Fit the 4FF SIM into the tray. Insert the end of each SIM card with the chamfered corner first and the SIM contacts facing upwards.

  1. Re-insert tray into the TX40.

  2. After all SIM cards are in place, replace the SIM slot cover.

Apply Dielectric Grease over SIM Contacts

Note Digi recommends using either the Loctite® LB 8423 Dielectric Grease or Synco Lube® Silicone Dielectric Grease.

  1. Use a sheet of paper or cardboard over the area where you intend to work.

  2. Use isopropyl alcohol and a cotton-tipped applicator to gently clean the SIM contacts. Using isopropyl alcohol requires a well vented environment. Demineralized water can also be used as an alternative.

  3. Once the surface is clean and dry, apply a small amount of dielectric grease in a thin layer over the contacts. Use a new cotton-tipped applicator to work the grease smoothy over the contacts. Apply gentle pressure.

  4. When the dielectric grease has been applied, insert the SIM into the SIM slot as described above.