Maintenance
1705A Spectrum Monitor 6-11
3. Determineand evaluate all trouble symptoms. This is accomplished by
isolating the problem to a general area such as an assembly. The block
diagram is a valuable aid in signal tracing and circuit i solation.
CAUTION. Use extremecare when probing with meter leads or probes, because of
the high component densityand limited access w ithin the instrument. The
inadvertent movementof leads or a probe could cause a short circuit or transient
voltages capable of destroyingcomponents.
Circuit board
mountedpins
PIN1
Moveable 10 --pinplug
Squarepin c onnector on
powers upply circuit board
PIN1
PIN1
24and 34 pin cir cuit
boardc onnectors on
Maincir cuit board
ROWA
ROWB
ROWB
ROWA
Figure6 -7: Multiplepin connectors used in the 1705A Spectr um Monitor
CAUTION. Always removethe assembly from the instrument prior to attempting
to replacea soldered-in component. SeeCorrective Maintenance for the correct
procedure.
4. Visuallyinspect the suspect assembly for obvious defects. Mostcommonly
these will be brokenor loose components, improperly seated components,
overheatedor burned components, chafed insulation, etc. Repairor replace