Lexicon 200, Service Manual

Page: 31 / 90

Lexicon
5-11
Encoder Test (9)
During the Encoder test, the Z80 microprocessor reads the value of the encoder, and then expects the next
value read from the encoder (when the encoder position is moved) will be at a predetermined incremental
value. Therefore, during the test the encoder must be rotated in a clockwise direction as it’s being tested, or
the test will fail.
Before the test is executed, the following test code will be displayed on the Diagnostic LEDs, along with the
test number on the 7-segment displays:
Test # Test Name Diagnostic LED
7-segment
display
9 Encoder EFFECTS “Rotry/Trmlo” 9
Pressing the Load button will execute the test.
When the test is executed, the leftmost 7-segment display will display an “r” to indicate the test is running,
and the rightmost digit of the 7-segment displays will indicate the value of the encoder’s current position.
The values range from (0-15).
MIDI Test (10)
This test will verify that the MIDI Input and MIDI Output/Thru circuits are working. The test will transmit data
out of the MIDI OUT jack and will attempt to read the data through the MIDI IN jack. To run this test, a 5 Pin
Male DIN to 5 Pin Male DIN Cable (also known as a MIDI cable) must be connected between the MIDI IN
jack and the MIDI OUT jack.
Before the test is executed, the following test code will be displayed on the Diagnostic LEDs, along with the
test number on the 7-segment displays:
Test # Test Name Diagnostic LED
7-segment
display
10 MIDI EFFECTS “Flange” 10
Pressing the Load button will execute the test.
Pressing the Tap/Cancel button will run the test continuously.
When the test is executed, the leftmost 7-segment display will display an “r” to indicate the test is running.
The pass/fail status of the test is displayed on the 7-segment displays and front panel LEVEL LEDs.
If the test passed, the (Green) LEVEL -30dB LEDs will light.
If the test failed, the (Red) LEVEL LEDs will light.
LED Test (11)
This test will verify that the LEDs and LED driver circuits are working. The test has essentially three
sections which perform the following functions:
1. Turn on all of the front panel LEDs, except for the LED segments on the 7-segment display.
2. Turn on all of the LED segments on the 7-segment display only.
3. Turn on each of the front panel LEDs and the LED segments on the 7-segment display individually.