Telos NX12 - Manual (Page 91)

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to turn on ISDN logging.
6.5 Troubleshooting Desktop Director Problems
Most problems with the Desktop Directors are cable related. First try a new cable. If that fails to
solve the problem, try the Desktop Director with a short cable plugged directly into each of the
Director Ports on the back of the Nx12.
Note that early production Call Controllers require a modification to operate with the Nx12.
Telos customer support can arrange for modification of these units at no charge.
Section 2 has details on the allowable wiring configurations for the Desktop Directors and other
control surfaces. There are distance and wiring restrictions. Note that when two Directors share
a single port an external power supply is required and the termination resistor must be removed
on the unit closer to the power supply.
The diagnostics on the Desktop Director and the Nx12’s status screen will help isolate bad wir-
ing or hardware. If errors are accruing try systematically swapping ports, and swapping Desktop
Directors, to see if the problem stays with a given port, Desktop Director, or cable.
6.6 Replaceable Modules and Hardware Servicing
WARNING - DANGER
Remove all connections, including the Telephone, Audio, and Electrical Mains
Power cord before opening the unit. Failure to do so could result in injury or
death. Do not open the unit unless you are qualified to do so.
Removal of the top plate gains access for service. To do so, remove the 10 Philips head screws.
Replaceable modules
While we do not expect you to do much repair or troubleshooting of the individual circuit
boards, the system does have several removable modules which can be replaced. The system has
the following replaceable modules:
Power Supply 1.
ISDN Line interface card: 2.
Part # 1701-00140 (U interface - USA and Canada); or
Part # 1701-00139 (S interface – Worldwide)
Analog POTS Line Interface part # 1701-00141
3.
AES option card part # 1701-00149 4.
Fuse Replacement
A fuse is located on the power supply PCB. If fuse replacement is required, note: For continued
protection against fire, replace fuse only with same type and value.
Access to the Main PCB
The main PCB, closest to the bottom of the enclosure, is mounted component-side down. You
can gain access to the component side of the PCB without taking it out by removing the bottom
plate of the enclosure box.