User manual

ECE 477 Final Report Spring 2004
Appendix H: FMECA Worksheet
Failure
No.
Failure Mode Possible Causes Failure Effects Method of
Detection
Criticality Remarks
RF-1 Frequency drift Any Capacitor filters
fail, any Inductor
filters fail, crystal
drift
Wireless
communication
failure (order not
received)
Observation Low Frequency drift could
interfere with local
wireless devices and
violate FCC regulations
RF-2 RF Signal loss Bandpass filter
failure
Wireless
communication
failure (order not
received)
Observation Low
PS-1 Output = 0V Failure in grounding
capacitors, shorting
power to ground
Loss of function,
possibly drained
battery, unit non-
functional
Observation Low
PS-2 LCD Screen off D5, Q1, C7, C47, or
other power supply
component fails
unit non-
functional
Observation Notable According to group
leader, “weakest part of
our design.” Still no
risk of injury.
MC-1 Improper or lack
of Input/Output
Power supply failure,
software
Unpredictable. Observation Low
H-1