Silva NX2, Service Manual

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71measurNX2.doc Page 1 Latest update: 13 Jan -03
7.1 SERVICE MEASURES
The Log transducer function can be checked by measureing the output pulses,
yellow to screen wire by oscilloskop or DMM showing ¨2,5 V when paddle wheel
is spinning.
See also § 4.3
If defect, the Log transducer has to be replaced as a complete unit.
Before assuming an electronic fault, ensure that the following is not the
reason:
a) Paddle wheel is not rotating freely due to sea grass, particles or bottom paint.
Check the opening edge of the through hull
fitting.
* If the boat is launched a piece of sandpaper can
be wrapt around the lower part of the dummy
plug and used for grinding the whole.
b) One ore both paddle wheel magnets are lost or have no magnitic strength.
Replace the paddle wheel if defect. P/N 18490.
TEMPERATURE SENSOR
The Temperature Sensor function is a termistor, which can be checked by
measureing the impedance, with a DMM between the White and screen wire:
At 15°C the resstance is about 22kohm
At 20°C the resstance is about 19kohm