User Manual

75
MN024-08
fibre to relevant ports after cleaning. If it doesn’t made TFLN red LED
switch off, follow next steps.
4. Disconnect the optical SC-APC connector from remote unit DL port, and
measure the output power P
OUT
(DL) at the corresponding fibre end. Then,
go to the TFLN side, disconnect the optical SC-APC connector from TFLN
DL port and measure the input power P
IN
(DL) coming out of the TFLN DL
port. Calculate the DL fibre attenuation A
DL
as A
DL
[dB] = P
IN
(DL) –
P
OUT
(DL)
c. If A
DL
> 4dB, then the fibre optic cable has some problems. Replace it
with a new one.
d. If A
DL
< 4dB troubleshooting procedure has not identified the problem.
Refer to supervision system or contact assistance.
TFAx
CaseL
Fig. 3.34a: Flow-chart describing the quick troubleshooting procedure on
Case LTFAx
star
t
Is the red LED
ON upon the
TFAx?
No
Yes
Yes
N
o
Verify if any external equipment
or any external alarm terminal
has some problems. Refer to
external alarm troubleshooting
(fig.3.34b)
Clean the SC-APC
optical adapters and
connectors
N
o
Yes
end
Is red LED upon
TFAx still ON?
Is red LED upon
TFAx still ON?
Optical cable or optical connections
are supposed to have problems on
DL path. Refer to fibre optic DL
troubleshooting (fig. 3.34c)