Roland JX-305 GROOVESYNTH Service Notes page 12

JX-305
Troubleshooting for Pedal test
Result of Test Check
No response Check Q4
Is signal level of the PEDAL change ?
Display remains "on" Check the condition of connection of
L9-12,R47,48
5. SW & LED Test
When Pedal Test ends normally, SW & LED Test runs
automatically.
(or in the initial display of the test mode, press [BANK 5]
while holding down [SHIFT])
5-1. When SW & LED test starts, the following display
appears.
Are All LEDs turn on ?
5-2. Press all buttons one by one. Then each button, names
of buttons appear on the display, and sounds.
And buttons that have corresponding LEDs are put out
its LEDs.
Press the all buttons for turning off the all LEDs.
• When you press [PLAY] button, press two times.
When you press [TEMPO & MEASURE], press three
times. And check that the Beat LED turns GREEN
and RED and off in order.
Is button name appeared on the display ?
Are all LEDs turn off ?
NOTE: If you press two buttons simultaneously, the LCD
display error.
5-3. If test ends normally, press [ENTER] to start next test.
Troubleshooting for SW & LED test
Result of Test Check
One of the LEDs Check the condition of connection of
dose not lit. LED.
Two or more LEDs Refer to the circuit diagram, check
do not lit. the transistor, buffer (74HC245), or
decoder (74HC138) around the LED
circuitry.
One of the SWs Check the diode and condition of
dose not work. connection of SW.
TWO or more SWs Refer to the circuit diagram, check
do not work. the decoder and transistor array.
LED stays on. Check the short circuit of signal lines
of LED.
6. AD Test
When SW / LED Test ends normally, AD Test runs
automatically.
(or in the initial display of the test mode, press [BANK 6]
while holding down [SHIFT].)
6-1. Connect the Expression to the Control Jack.
6-2. When AD test starts, the JX-305 into standby mode.
Move each knob, name and value of the knob are
displayed.
Move the all knobs and sliders fully one by one.
(excluding "VOLUME")
NOTE: If you move the knobs and Bender, Modulation, Ctrl
Pedal, knobs simultaneously, the LCD display error.
To abort a command, press [BWD] button.
Press on the Control Pedal.
Check that the value changes 0 from 127.
Check the mid value 64 when move Env Depth.
12
Sep. 1998