Chapter 10

Troubleshooting

This chapter provides quick easy-reference troubleshooting tables for the Model XM128 ISDN Digital Modem. For troubleshooting purposes, the Model XM128 modem performs its own diagnostic tests, which can provide information about each of its functions.

The Model XM128 modem provides several diagnostic capabilities:

Power-on self-test

Local digital loopback tests

Diagnostic command

Modem reset

Power-on Self-test

At each power-up sequence or upon a reset command from the panel, the Model XM128 modem tests the ROM code checksum, system RAM memory, EEPROM, digital and analog circuit calibrations, and analog circuit calibrations.

Table 10-1 summarizes the power-on self-test of the Model XM128 modem.

Table 10-1.

Power-on self-test

 

 

 

 

 

 

 

 

 

 

Test Sequence

 

LED LNK

LED B1

LED B2

LED AA

Test Description

 

 

 

 

 

 

 

1

 

On

Off

Off

Off

Memory test

 

 

 

 

 

 

 

2

 

Off

On

Off

Off

ISDN chip interface test

 

 

 

 

 

 

 

3

 

Off

Off

On

Off

ISDN chip functional test

 

 

 

 

 

 

 

4

 

Off

Off

Off

On

HDLC functional test

 

 

 

 

 

 

 

Troubleshooting

10-1

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NETGEAR XM128 ISDN manual Chapter Troubleshooting, Power-on Self-test, Test Sequence, Test Description