HP 3468A - Test and Reset Functions

The 3468A self test performs several checks on the digital and A/D converter cir-
cuitry of the instrument. A failure in any of these four areas is indicated by an er-
ror message in the display. When the self test is complete, the 3468A resets to
its turn-on state.
Do This
press: wESIY This initiates the functional tests of
the digital circuitry in the 3468A. The
SELF TEST starts by turning every seg-
ment in the display on (except the top
dot on the colon) for about 2 seconds.
Following this, a complete power-on
SELF TEST is performed. If the test
passes, the 3468A returns to its
power-on state. If the test fails, an er-
ror message appears on the display in-
stead. After the error message is
displayed, the 3468A attempts to
operate normally. The turn-on state for
the 3468A is:
Function: DC volts
Range: Autorange on
Display: 5 1/2 digits
Trigger: Internal trigger
Auto-Zero: on |
Table 2-6. Self Test Error Messages
ERROR 1 - Calibration RAM error. This may indicate that only certain func-
tion and range combinations are not calibrated as indicated by
the CAL” annunciator. However, the 3468A will continue to
operate correctly on all other functions and ranges where the
CAL annunciator is not lit.
ERROR 2 -—- Internal microprocessor RAM error
ERROR 4 -— Internal microprocessor ROM error
ERROR 8 A/D Converter error
If
more
than
one
error
is
detected,
then
‘ERROR
dd’
will
appear
in
the
display.
The
decimal
number,
dd,
represents
the
summation
of
the
individual
error
message
numbers.
For
example,
ERROR
6
would
indicate
that
errors
2
and
4
were
detected.
For
all
failures
refer
to
the
3468A
Service
Manual.
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