Tektronix 7834

7834 Instruction
SERVICE SAFETY INFORMATION
The following
are
safety
precautions which
appear in
the servicing information sections
of
this manual . This Service Safety
Information is in addition to the Operators Safety
Information given
previously .
Do Not Service
Alone
Do not attempt internal service or adjustment unless another person, capable of rendering first aid and resuscitation, is
present .
Exercise
Care When
Operating Instrument with Covers Removed
Dangerous potentials exist at several points throughout this instrument . When the instrument is operated with the covers
removed, do not touch exposed connections or components . Some transistors have voltages present
on
their
cases .
Disconnect
power before cleaning the instrument or replacing parts .
Disconnect Instrument Power
To avoid electric-shock hazard, always disconnect the 7834 from the power source before removing or replacing components .
To avoid electric-shock hazard, disconnect the instrument from the power source before soldering .
Silicone Grease Handling
Handle silicone grease with
care
. Avoid
getting
the silicone
grease
in your eyes . Wash hands thoroughly after use .
Exercise Care When Servicing Power Unit
The power supply unit has
been
tested at the factory
to
ensure safe
operation . Improper repair of this unit can result in
hazardous potentials
on the
instrument chassis .
Do not
remove the plate
insulator,
block
insulator, or transistor shield from
the heat-sink . (See the exploded view drawing of the power supply unit
for
the location
of
these components
.)
Disconnect the instrument from the power source and allow the line storage capacitors
to
discharge
before removing the
power-unit
cover . The line
storage
capacitors remain charged with high-voltage
do
for several
minutes after the line power is
disconnected unless they are manually discharged . A warning-indicator neon bulb, located on the Power-Supply Inverter
board, flashes when this
stored
voltage exceeds about
80
volts
. Do not remove the power-unit,cover while this light is
flashing .
Use extreme caution when troubleshooting in the power-supply unit, to
avoid electric shock
.
Stored do potentials on the
Power-Supply
Inverter
circuit board remain
long
after the instrument is disconnected from the power source . Verify that the
power-cord plug is disconnected and that the line storage capacitors (C1216 and C1217) are completely
discharged before
attempting any repairs or ohmic measurements . (A warning-indicator neon bulb, located on the Power-Supply Inverter
board,
flashes when this stored voltage exceeds about 80 volts . However, simply because the neon bulb is not flashing does not mean
that the capacitors are fully discharged .)