NEC FA Series Installation And Maintenance Manual page 98

(2) Problem with the LED modules
To display more details, click "Monitoring", and then click "Receiving card" on the screen that is displayed.
English - 96
When the display is red,
there is a problem with the
LED module operation.
In the example shown on the left, the
following problems must be considered.
- Signal loss between the screen of the
3rd row 3rd column and the screen of
the 2nd row 3rd column
→ Check the internal LAN cable.
- Problem with both power units of the
screen of the 2nd row 3rd column
→ Check the rear indicator (red) to see
if it is lit.
There is no problem
if it is lit red.
If it is not lit, the power unit is
probably broken. (Replacing the power
unit)
- Problem with the receiving card of the
screen of the 2nd row 3rd column
→ Check that the receiving card is
securely connected. If there are no
connection problems, the receiving
card may malfunction. (Replacing
the receiving card)