Orban OPTIMOD-FM 8700, Operating Manual

Page: 285 / 390

OPTIMOD-FM DIGITAL MAINTENANCE
4-9
Your Optimod constantly monitors the dual-redundant power supplies with au-
tomatic switching. If both supplies are good and connected to the AC line, the
front-panel power light will glow green. If either supply has been disconnected
from the AC line or has failed, the power light will be red and will flash on and
off.
To access system diagnostics,
locate
to
S
YSTEM
S
ETUP
> D
IAGNOSTIC
and scroll
through the screens until you see
P
OWER
S
UPPLY
#1
X
and
P
OWER
S
UPPLY
#2 =
X
,
where x is
G
OOD
or
B
AD
.
Power supply #1 is physically on top.
In PC Remote, system diagnostics are available from PC Remote in the Help
menu. They can also be fetched via the
ST
command in the API (see step on
page 2-56).
The green LED power light on the upper right of the front panel display moni-
tors the DC power supply outputs. If one or more power supply voltages are out
of tolerance, red flashes will report them according to the table below. If there
are multiple values out of tolerance, they are reported one after another in a
continuous loop, with one green flash indicating the beginning of each count.
See Table 4-1 on page 4-8.
3. Check Analog Output Trim Levels.
A) Verify 8700i software controls are set to their default settings. (Refer to page
4-7.)
B) Feed the 8700i output with the built-in 400 Hz Test tone.
To turn on the T
EST
tone:
a) Navigate to System Setup .
b) Choose Test Modes .
c) Navigate to the Tone button and press Enter .
C) Connect the audio voltmeter to the Left Analog Output.
D) Adjust output trim VR200 to make the meter read +10.6 dBu. (0 dBu = 0.775V
rms.) Verify a frequency reading of 400 Hz.
E) Verify THD+N reading of <0.05% (0.02% typical) using a 22 kHz low pass filter
in the distortion analyzer.
F) Recall the bypass preset: Navigate to the
B
YPASS
button and press
E
NTER
.
Bypass defeats all compression, limiting, and program equalization but
retains preemphasis.
G) Verify a reading (noise) of <–80 dBu at the output of the unit.
H) Repeat steps (C) through (G) for the Right Analog Output, adjusting output
trim VR201 at step D)
4. Check frequency response of Analog I/O.
A) Verify 8700i software controls are set to their default settings. (Refer to page
4-7.)