VAF instruments OILCON MARK 6M, Technical Manual

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15 TROUBLE SHOOTING AND FAULT FINDING
15.1 INTRODUCTION FAULT FINDING GUIDE
The first requirement when attempting to find a fault in the system, is to ensure that the monitor is
correctly set up to run. A large number of service problems can be directly related to a simple
mechanical fault, which appears to cause a large number of seemingly unrelated problems. It is
essential to check before delving too deeply, that all hand-valves in the system are open; that the
fresh water supply is available and clean and free of any contaminants; that the air supply to the
EPU is on; that electrical supply to the pump is on; and that the electrical supply to the MCU and
EPU is on.
It is also important to note that most service problems are mechanical faults and not electronic
faults. On the whole, electronic systems are much more reliable than the mechanical components
connected to them. However, when a fault occurs, the tendency is to distrust the electronic systems
and look for faults in the electronic parts, discounting the mechanical parts. This tendency should be
reversed.
The emphasis in this fault finding guide and the following “Repair” section is on mechanical repair
and overhaul. Indications are given to assist in electronic repairs, but it is expected that most fault
will be rectified by complete board replacement, rather than component replacement. Therefore, it is
indicated which board is likely to be the source of the particular problem.
SAFETY PRECAUTIONS: MAKE SURE THAT ALL SAFETY REQUIREMENTS AS
DESCRIBED IN SECTION 4.1 ARE MET BEFORE ANY WORK IS COMMENCED.
CAUTION:
The printed circuit boards have CMOS components which may be damaged by
electrostatic discharges.
Observe correct procedures for handling CMOS components. It is also recommended
to store the circuit boards in electrostatic proof cases.