Chapter 2. Installation TSU LT User Manual32 © 2002 ADTRAN, Inc. 61202060L4-1Self-TestWhen ThenA power-up orcommanded self-test occursThe LCD displays ADTRAN TSU INITIALIZING and the LEDsilluminate sequentially.The self-test iscompleted with nofailures detectedThe LCD momentarily displays ALL TESTS PASSED.A failure isdetectedIt is displayed in the LCD window.The automatic self-test consists of the following tests:• Board level tests• Random access memory (RAM) tests; erasable programmableread only memory (EPROM) checksum.• On-board data path. Sending a known test pattern through anon-board loop.• Unit level tests• Front panel LED verification.• Phase lock loop verify.
