Lcd Test; Key Test - Lexicon 960L Service Manual

NOTE: This test requires an External Keyboard connected to the 'AUX' port. Otherwise the test will fail
when an External Keyboard is not present. Diagnostic error messages are also sent to the Debug Port to
indicate when a failure has occurred as shown in the example below.
**ERR**KB01** TXRDY= 0. should be 1, GPIO= fffc7ec
**ERR**KB02** IBFULL= 1 should be 0, Stat= 12, GPIO= fffc7ec
**ERR**KB03** Keyboard Timeout
TEST 7: Host Port (Loop Back) Test
This test checks for the presence of a Loop Back Plug connected to the HOST port of the LARC2 by
sending 8 characters out the port, and monitors any data that is received. The data received is then
compared to what was sent.
NOTE: This test requires a Female RS-422 Wraparound Plug installed in the 'HOST' port. Otherwise the
test will fail when the Loop Back Plug is not present. A diagnostic error message is also sent to the Debug
Port to indicate when a failure has occurred as shown in the example below:
Loop Back Not installed
TEST 8: Keystuck & Fader Touch Test
This test checks for stuck keys on the Main Board, or if any of the Faders were being touched during the
Power On Diagnostic tests.

LCD Test:

This test is used to verify the operation of LCD display circuitry by displaying various attributes of the LCD
display, which includes a display of vertical color bars, dimming the LCD display, turning the LCD display off
and on, and displaying a white screen with a red border. When the test is executed, the 'ENTER' key is
used to advance (step) through six different screens to verify the operation of the LCD display, as described
in the table below:
STEP: DESCRIPTION:
1 The LCD displays vertical color bars at full brightness
2 The LCD displays Vertical Color Bars that are dimmed
3 The LCD display is turned off
4 The LCD displays Vertical Color Bars that are dimmed
5 The LCD displays Vertical Color Bars at full brightness
6 The LCD displays a white screen with a red border
NOTE: The white screen with a red border (from Step 6 above) is the best screen to use for verifying there
are no defective pixels (which would appear as black dots) on the LCD display. This is also useful for
checking the alignment of the LCD display with the Display Housing assembly.

Key Test:

This test is used to verify the operation of the Fader Touch circuitry for each of the (8) faders, and the (45)
keys on the Main Board keypad. When the test is executed, the (8) faders are tested first, followed by the
(45) keys. During the test, the names of the keys pressed are sent to the LCD display, and also to the
Debug Port.
Lexicon
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