NV-450M/S: G.fast Master Modem+ G.fast / VDSL2 / V35b Slave Modem USER’S MANUAL Ver. A.4
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System Diagnostics
Power and Cooling Problems
If the POWER indicator does not turn on when the power cord is plugged in, you may have a problem with the power outlet,
power cord, or internal power supply as explained in the previous section. However, if the unit power is off after running for
a while, check for loose power connections, power losses or surges at the power outlet. If you still cannot isolate the
problem, then the internal power supply may be defective. In this case, please contact your local dealer.
Installation
Verify that all system components have been properly installed. If one or more components appear to be malfunctioning
(e.g. the power cord or network cabling), test them in an alternate environment where you are sure that all the other
components are functioning properly.
Transmission Mode
The default method of selecting the transmission mode for RJ-45 Ehernet ports is 10/100/1000 Mbps, for RJ-11 line port
are auto-follow CO side band profile for NV-450S. Therefore, if the Link signal is disrupted (e.g. by unplugging the network
cable and plugging it back in again, or by resetting the power), the port will try to reestablish communications with the
attached device via auto-negotiation. If auto-negotiation fails, then communications are set to half duplex by default. Based
on this type of commercial-standard connection policy, if you are using a full-duplex device that does not support
auto-negotiation, communications can be easily lost (i.e. reset to the wrong mode) whenever the attached device is reset
or experiences a power fluctuation. The best way to resolve this problem is to upgrade these devices to a version that
support Ethernet auto-negotiation.
