User guide

45 Mbps Backhaul User Guide

Issue 3, December 2004 Page 76 of 113

7 Fault Finding

If communication has been lost with the unit at the near end of the link then there may be a hardware fault with

the wiring, network or hardware. Go to the hardware section below. If communication with the far end of the

link is lost then go to the radio section below.

7.1 Hardware

If there are problems suspected with the link hardware the following procedure is recommended.

The following diagram illustrates the main system connections.

Figure 42 Main System Connections

7.1.1 Power

Check the power LED at each end of the link. If the power lights are illuminated go to the Ethernet section

below. If at either end they are not illuminated then

check the Ethernet LED. If neither are illuminated then

there is no voltage on the power wires to the ODU.

1. Check that the mains power is connected and switched on.

2. Check that the lamp illuminates if the ODU connector is disconnected at the PIDU. (Remove

the PIDU cover).

a. If it does illuminate then either the ODU is drawing to much current, or the power

wiring to the ODU is short circuit or the PSU is supplying insufficient power. The

likely fault can be determined by removing the jumper (J906), found inside the

removable cover of the PIDU, and measuring the current taken with an ammeter

placed across the 2 jumper pins. This is normally 10mA without the ODU connected

and 300mA to 1A when the ODU is connected.

b. If it does not illuminate then recheck that power is applied to the PIDU by

measuring the voltage across +55V and 0V pads inside the removable cover in the

PIDU. Check that the PIDU is not short circuit by measuring the impedance across

the Power connector. Is the lamp faulty?

The power indicator LED should be continually illuminated.