Alesis DEQ224 Service Manual page 24

Front Panel Sub Assembly Test CON'T
7) In order, press Band Button 4 through Band Button 24.
Verify that when the button is held, that the column above the
button lights, that the number corresponding to the button is
shown in the seven-segment display, and that when the button is
held, that the LEDs that are on do not flicker.
Verify that when the seven-segment display shows the button
number, that the display does not flicker, and that all the
LEDs for the appropriate number are lit, and that no extra
segments are lit.
Problems with no response or flickering LEDs indicates poor or
failed switch, and the test has FAILED.
problem with the numbers displayed in the seven-segment
display, then the display has also FAILED.
Failure of this inspection indicates that the DUT cannot
continue further testing.
8) Press the DOWN button.
Verify that the Channel A signal AND clip LEDs light, and that
when the button is held, that the LEDs that are on do not
flicker.
Problems with no response or flickering LEDs indicate poor or
failed switch, OR failed LED.
turn on at the same time.
test has FAILED.
Failure of this inspection indicates that the DUT cannot
continue further testing.
9) Press the UP button.
Verify that the Channel B signal AND clip LEDs light, and that
when the button is held, that the LEDs that are on do not
flicker.
Problems with no response or flickering LEDs indicate poor or
failed switch, OR failed LED.
turn on at the same time.
test has FAILED.
Failure of this inspection indicates that the DUT cannot
continue further testing.
If there seems to be a
Be sure to verify that BOTH LEDs
Either type of problem indicates the
Be sure to verify that BOTH LEDs
Either type of problem indicates the