IS12 Depth & Combi

Background

Simrad have been investigating some isolated instances of IS12 Combi and Depth installations in which the depth reading is intermittent.

Investigation

Investigation of returned units points towards a component that under some circumstances can become mechanically stressed, leading to a small drift in the frequency of the depth pulse. The nature of the fault and the variability of stress mean that it is difficult to isolate which units are most affected. The percentage of units affected is however relatively small. It is thought that the effect occurs mostly in units that are less than 12 months old.

Modification Details

A modification has been introduced that removes the stressing effect and ensures that the oscillator frequency is correct. The modification is a factory fit; it is not possible to modify units in the field.

Implementation

This modification has been introduced from serial numbers:
IS12 Combi’s from serial number WD2587
IS12 Depth’s from serial number WD2627

Swap Out

If you receive any reports of IS12 Combi or Depth units that are within warranty and display intermittent depth behavior, please ensure routine checks on cabling and connections are carried out first. Should the issue persist, the display head can be swapped out by advance exchange (subject to stock availability). This means we can provide the replacement unit at normal price and issue a credit upon return of faulty unit. A purchase order must be provided and the the returned instrument must not be physically damaged or have other defects outside of warranty conditions.