Paradyne 6800 - Manual (Page 343)

Maintaining Multiplexers
C-3 6800-A2-GN22-30 January 1997
If the multiplexer control processor experiences faults, its LED display will indicate the
nature of the fault (if possible). For example, if the LED reads 333, the control processor is
performing diagnostics. To identify a fault, read the rightmost digit of the LED display for
the control processor card or cards. The codes correspond to status conditions, and are
described in Steps 4, 5, 6, and 7.
CAUTION
In the following procedures where you are instructed to check
power connections, you should make a visual inspection only.
To avoid electrical shock, be sure to turn off power to the
multiplexer before you examine any power connection.
4. If the control processor’s LED display is blank, perform the following steps:
a. Make sure the control processor is secure in its shelf slot.
b. Check the power distribution connections. Figures C-1 and C-2 show the locations of
these connections on the 740 multiplexer (both with and without the expansion shelf).
Figure C-3 shows the location of these connections on the 745 multiplexer.
c. Check the power supply monitor and control connections. Refer to Figure C-1, C-2, or
C-3 for the connections appropriate to your multiplexer.
d. Check the 4336 power supply monitor and control connections. Refer to Figure C-4 or
C-5. If one of these power supplies has failed, the light on the front of the 4336 power
supply may be flashing.
J1
P11 P12
J1
power connections
power
switch
AC
fuse
power
Power
Distribution
Connection
Power
Monitor and
Control
Connection
490-11631
Figure C-1. Power Connections for 740 Multiplexers without Expansion Shelf