Electronics Replacement

Model 122M P8 Mini Interface Meter: Electronics Replacement


Tools and Materials Needed

  1. 122M (CSA) Complete Electronics Package (#111329)
  2. Phillips or Robertson (Square Head) Screwdriver
  3. Small Wrench or Pliers
  4. Small Flat Screwdriver
  5. Soldering Iron and Wire
solinst 122m interface meter complete electronics package

122M (CSA) Complete Electronics Package

solinst 122m p8 mini interface meter component locations diagram

122M P8 (CSA) Mini Interface Meter indicating the location of components


  1. Place the reel on a flat surface, with the faceplate up. Remove the battery from the faceplate.
  2. Use the Phillips or Robertson screwdriver to undo the three screws holding the faceplate to the hub.
  3. Remove the faceplate and disconnect the 3 pin Molex connector that attaches the faceplate electronics to the cable.
  4. Use the soldering iron to unsolder the two wires from the battery tray.
  5. Use the wrench or pliers to unscrew the nut retaining the On/OFF button on the front of the faceplate.
  6. By hand, unscrew the Sonalert retaining ring from the front of the faceplate.
  7. Remove the electronics assembly from the back of the faceplate (PCB assembly, Sonalert, On/OFF button, and product indicator light).
  8. Note:

    The red product indicator light lens will remain in the faceplate.


  9. Line-up and insert the On/OFF button, product indicator light, and Sonalert of the new electronics assembly, through the back of the faceplate. The light will seat in the lens.
  10. Use the retaining nut to secure the on/OFF button to the faceplate and the retaining ring to secure the Sonalert.
  11. Solder the two wires to the battery tray. The wire with the brown fuse goes to the positive terminal.

back view of solinst 122m p8 sc100 mini interface meter faceplate with electronics locations identified

Back of 122M P8 (CSA) SC100 Mini Faceplate showing the location of electronics

  1. Connect the 3 pin Molex connector to the cable connector.
  2. Replace the faceplate by fastening three screws and replace the batteries.
  3. With the Probe in a glass of tap water and product, turn the Mini Interface Meter on. A steady tone and light indicates a product, while an intermittent tone indicates water. If the buzzer or light do not activate, check the soldered and Molex connections.