MAINTENANCE
Each power supply has one green LED on its front that can be seen through
the fan assembly. The LED is visible through the ventilation slots on the front
cover, but the cover must be removed for diagnostic and service purposes.
This LED is always lighted when the system is receiving 5.1 volts power. The
LED is dark when there is a failure in the +5 volt power supply or power
connections, or when there is a short on the backplane.
If the green LED on the power supply is dark, first make sure that the cabinet
is receiving ac power. Be sure that the fans are running, that the connection
to building ac power has been made correctly, and that the power rocker
switch is in the ON (1) position.
See DANGER below. Then check the
internal power connections (see Figure 4-8).
Danger:
The power cord must be unplugged before the rear
cover is removed. Simply setting the power switch to
OFF is not sufficient.
4-67
Summary of Contents for Network Adapter 25
Page 1: ...AT T AT T System 25 Installation and Maintenance Manual 555 540 103 B November 1995 ...
Page 18: ...APPENDIX F Administration Error Messages GLOSSARY I N D E X F 1 G 1 I 1 viii ...
Page 31: ...INSTALLATION MOUNTING CENTERS WHEN FLANGES ARE OVERLAPPED Figure 2 2 617A Panel 2 7 ...
Page 33: ...INSTALLATION Z21OA1 ADAPTER Y ADAPTER WP90851 L1 858A ADAPTER Figure 2 3 SIP Adapters 2 9 ...
Page 50: ...INSTALLATION Figure 2 10 Three Cabinet System Front View With Covers Removed 2 26 ...
Page 51: ...INSTALLATION Figure 2 11 Position of Shorting Plugs on CPU Memory Circuit Pack 2 27 ...
Page 72: ...INSTALLATION UPPER ADAPTER MOUNTING CLIP Figure 2 18 Mounting Adapters ...
Page 85: ...INSTALLATION 2 61 ...
Page 92: ...INSTALLATION 2 68 ...
Page 103: ...INSTALLATION Figure 2 32 10B Emergency Transfer Unit 2 78 ...
Page 104: ...INSTALLATION Figure 2 33 Emergency Transfer Unit Connections 2 79 ...
Page 109: ...INSTALLATION Figure 2 35 Attendant Console With DXS Console 2 84 ...
Page 146: ...INSTALLATION 2 119b This page intentionally left blank November 1995 ...
Page 153: ...INSTALLATION This page intentionally left blank 2 124b November 1995 ...
Page 223: ...MAINTENANCE Figure 4 2 Clearing Supply Troubles Sheet 1 of 2 4 47 ...
Page 224: ...MAINTENANCE Figure 4 2 Clearing Power Supply Troubles Sheet 2 of 2 ...
Page 225: ...MAINTENANCE Figure 4 3 Clearing CO Trunk Troubles 4 49 ...
Page 226: ...MAINTENANCE Figure 4 4 Clearing 4 Wire Tie Trunk Troubles Sheet 1 of 4 4 50 ...
Page 227: ...MAINTENANCE Figure 4 4 Clearing 4 Wire Tie Trunk Troubles Sheet 2 of 4 4 51 ...
Page 228: ...MAINTENANCE Figure 4 4 Clearing 4 Wire Tie Trunk Troubles Sheet 3 of 4 4 52 ...
Page 229: ...MAINTENANCE Figure 4 4 Clearing 4 Wire Tie Trunk Troubles Sheet 4 of 4 4 53 ...
Page 231: ...Figure 4 6 Clearing Tie Trunk Troubles Sheet 1 of 5 4 55 ...
Page 232: ...MAINTENANCE 6 7 8 9 10 Figure 4 6 Clearing Tie Trunk Troubles Sheet 2 of 5 4 56 ...
Page 233: ...MAINTENANCE Figure 4 6 Clearing Tie Trunk Troubles Sheet 3 of 5 4 57 ...
Page 234: ...MAINTENANCE Figure 4 6 Clearing Tie Trunk Troubles Sheet 4 of 5 4 58 ...
Page 235: ...MAINTENANCE Figure 4 6 Clearing Tie Trunk Troubles Sheet 5 of 5 4 59 ...
Page 236: ...MAINTENANCE Figure 4 7 Clearing Paging Equipment Troubles ...
Page 250: ...MAINTENANCE Figure 4 9 System Cabinet Backplane Wiring Side Sheet 2 of 2 4 74 ...
Page 251: ...MAINTENANCE Figure 4 10 TDM Signal Designations on Cabinet Backplane 4 75 ...
Page 252: ...MAINTENANCE Figure 4 11 Power Designations on Cabinet Backplane 4 76 ...
Page 263: ...MAINTENANCE Figure 4 12 Clearing Virtual Facilities Troubles Sheet 1 of 3 ...
Page 264: ...MAINTENANCE Figure 4 12 Clearing Virtual Facilities Troubles Sheet 2 of 3 4 87 ...
Page 265: ...MAINTENANCE Figure 4 12 Clearing Virtual Facilities Troubles Sheet 3 of 3 4 88 ...
Page 271: ...MAINTENANCE Figure 4 13 Clearing Switched Loop Attendant Console Troubles Sheet 1 of 5 ...
Page 272: ...MAINTENANCE 4 13 Clearing Switched Loop 2 of 5 Console Troubles Sheet 4 95 ...
Page 273: ...MAINTENANCE Figure 4 13 Clearing Switched 3 of 5 Loop Attendant Console Troubles Sheet 4 96 ...
Page 274: ...MAINTENANCE 4 13 Clearing Switched 4 of 5 Console Troubles 4 97 ...
Page 321: ...APPENDIX E Administration Codes and Data This page is intentionally blank E 2 b ...