Why did a Tracer I sent for repair return with a different Serial Number?
There are two reasons that this could happen; which reason depends on the model of Tracer being serviced. 1. MPIII Tracers will change Serial Numbers for a different reason. If the MPIII probe is damaged or needs to be replaced, the Tracer will be returned with a different Serial Number. The design of the MPIII Tracer includes the probe as part of the body assembly, unlike the earlier Tracers where they were separate items. The Serial Number is laser- etched onto the MPIII body before assembly. During service for probe damage, a new body (with a new Serial Number) must be used. 2. Older Tracers (those built before 1996) had a circuit type called a hybrid. They had serial numbers which were either MTSxxxxx or STxxxxx. While state-of-the-art at the time they were developed, they consumed sufficient power that there was a need to design a magnetic switch to prevent battery depletion while not in use. The switch was activated by the presence of a magnet in the Tracer’s Storage Module. In 1
