7. Common Failure Analysis and Troubleshooting
Power on, the front panel
display screen and power
Indicator are both off.
Switch powering power supply couldn’t
start; equipment; internal DC
power supply is not working.
Check if the power supply is normal
(should be AC: 110V-250V). If the
Supply voltage is normal, it could be a
Failure of switching power supply
module. Please contact the dealer or
our company
Power on, the display screen is
off, only the power indicator is
on.
The internal microprocessor is not
working.
Please contact the dealer or our
company.
Power on; the optical output
power displayed on the front
panel display screen and laser
status indicator are both normal,
but the actual measured optical
output power is low.
1. The poor quality of the test
jumper.
2. The active fiber connector or
adapter may be contaminated.
3. The ceramic tube in the adapter
may have been broken.
1. Replace with good quality test
jumper.
2. Clean the contaminated active fiber
connector or adapter. Specific operation
methods see "The clean and maintenance
method of optical fiber connector".
3. Replace the damaged adapter.
After initial startup, the image of
the optical contact point has
obvious netlike curve or large
particles highlights.
1. The received optical power of
the optical contact point is too
high; the output level of the
optical receiver module is too
high and intermodulation index
of RF signal deteriorates.
2. The RF signal input of the
optical transmitter is too high;
beyond the device AGC
control range, results in
deterioration of the
intermodulation index.
3. The intermodulation index of
RF signal input of the optical
transmitter itself is poor.
1. Check the receiver optical power
of the optical contact point and
make appropriate adjustments.
2. Check the input level of the optical
transmitter RF signal, and adjust to
the device required input range.
(RF signal input level should be
72-88dBµV).
3. Check the intermodulation index of the
RF signal input of the optical transmitter
And make appropriate adjustments.
After initial startup, the image of
the optical contact point has
obvious noises.
1. The received optical power of
the optical contract point is not
high enough, results in decrease
of C/N.
2. The RF signal level input of the
optical transmitter is too low;
make modulation degree of the
laser is not enough.
3. The C/N index of system link signal
is too low.
1. Recover received optical power of the
optical contract point by cleaning the
active fiber connector or. Specific
operation methods see “Clean and
maintenance methods of optical
fiber connector”.
2. Check the RF signal level input of the
optical transmitter and adjust to the
device required input range.
(72--88dBµV). When the input channel
number less than 15, set to the MGC
control mode.
3. Use a spectrum analyzer to check the
system link C/N and make appropriate
adjustment. Make sure the system link
Signal C/N > 51dB.
