Black Box ME445C-530, ME444AE-R3, ME445C-X.21, ME445C-35 Calling Black Box, Local digital loopback

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CHAPTER 6: Troubleshooting

4.After the test is complete or the fault has been corrected, restore the DIG button to its normal position.

LOCAL

DTE

DIG

DEPRESSED

XMTR

RCVR

RCVR

XMTR

DATA

CLK

REMOTE

DTE

DATA

CLK

Figure 6-6. Local digital loopback.

6.7 Calling Black Box

If you determine that your line driver is malfunctioning, do not attempt to alter or repair the unit. It contains no user-serviceable parts. Contact Black Box Technical Support at 724-746-5500. The problem might be solvable over the phone.

Before you do, make a record of the history of the problem. We will be able to provide more efficient and accurate assistance if you have a complete description, including:

•the nature and duration of the problem.

•when the problem occurs.

•the components involved in the problem.

•any particular application that, when used, appears to create the problem or make it worse.

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Contents Kbps Line Driver FCC and IC RFI Statements Safety Warnings Declaration of Conformity Kbps Line Driver V.35, RS-530, or NOM Statement Trademarks Used in this Manual Contents Specifications Flow Control NoneSpecifications Introduction Physical DescriptionLine driver block diagram Functional DescriptionModulation Timing Applications Point-to-point applicationTail-circuit application Placement of the Standalone Version ConfigurationInstalling the Card Version in the RackNest 2/14 Description of the Racknest 2/14’S Power Supply Configuring the Standalone or Card Version User-configurable optionsUser-configurable options Layout of the 256-kbps Line Driver circuit board Kbps Line Driver V.35, RS-530, or Installation Installing the Standalone Version in 19-Inch RacksInstalling a single unit in a 19-inch rack Installing two units in a 19-inch rack Installing the 256-kbps Line Driver Rackmount Card Version Installing a card in the RackNest 2/14RackNest 2/14 illustrated Function Installation Kbps Line Driver V.35, RS-530, or Signal ITU-TSS Lead Name Abbrev Circuit Type Rack Norm Nest PIN Pinout of the V.35 standalone’s M/34 connector DB25 DA15 Connecting Data Cables Line Connection Installation Controls and Indicators OperationOperation Operating Procedure IndicatorsBit-Error-Rate Tester Bert TroubleshootingLoop Tests Bert using loops Modem Self-Test Local Analog LoopbackLocal analog loopback Remote Digital Loopback Local Digital Loopback Remote digital loopbackCalling Black Box Local digital loopbackShipping and Packaging Appendix Maximum Distances 19-AWG 22-AWG 24-AWG 26-AWG Kbps MilesCopyright 2004. Black Box Corporation. All rights reserved