Welch Allyn Grason-Stadler GSI 17 1717-9700, Service Manual

Page: 41 / 104

4.9.3 DISPLAY DIAGNOSTIC TES TT (D2)
TEST DESCRIPTION
This test provides a means of visually testing the operation of
all LCD segments and LEDS. When the test is selected, the code
"D2
will be displayed on the HL display for 2 seconds. All
segments and LEDs will then be blanked for 2 seconds, after which
all segments and LEDs will be turned on for 2 seconds to allow
inspection for any displays which do not turn on. All
segments/LEDs will then be turned on individually for 1 second in
a left to right, top to bottom sequence to allow for inspection
of
any
shorts between segments. After all segments/LEDs
have
been sequenced through all segments/LEDs will be turned back on
to indicate the completion of the test.
During this test the low battery voltage monitoring will not be
performed since the display is not available to indicate a low
battery condition.
TEST INITIALIZATION
When switched into the display diagnostic test, the instrument
will be initialized as follows:
Tone Type = Current selection
Frequency = Current selection
Stimulus M
UX
= Current position
Channel = OFF
Attenuator position = 255
+10 dB Pad = Out
Transducer Routing = None
HL Display = Displays "D2"
for 2 seconds and then the
display test starts
Response LED = OFF
Stimulus On LED = OFF
Low Battery Segment = Current state
Segment = OFF
DESCRIPTION OF CONTROLS
All controls except the Cal/Normal switch are inactive during
this diagnostic test. Operations of all other controls will be
ignored.
DESCRIPTION OF DISPLAYS
All LCD segments and LEDs are tested during this diagnostic test.
There are no parameter or status information displayed on the
displays.