Test Mode - Boss GT-3 Service Notes

GT-3

TEST MODE

CAUTION:The user data will be lost during the test mode. Save the
user data on an external memory (e.g. sequencer, MC-50MK2)
before entering test mode. For saving procedure, refer to
"Transmitting/receiving data via MIDI" in this manual.
Test options
1. Display
2. LCD Contrast
3. Switch
4. EXP PEDAL
5. Battery
6. MIDI IN/OUT
7. OUTPUT D/A
8. DS A/D/A [GAIN LOW ]
9. DS A/D/A [GAIN HIGH]
10. DS A/D/A [OVERDRIVE]
11. DS A/D/A [CV CHECK ]
12. EXT OD CHECK
13. INPUT A/D
14. DSP Pitch Interrupt Signal
15. Noise (IN→OUT)
16. Noise (EXT)
17. Noise (DS)
18. Calibrate EXP
19. Factory Load
Tools required
• Expression Pedal(Roland EV-5)
• MIDI cable
• Noise meter
• Oscilloscope
• Audio generator
• Blank plug
Entering test mode
(1) Start from the "1. Display" test.
Pressing buttons [MASTER] and [PEDAL/ASSIGN], turn the
power on.
The LCD will show the version of ROM firmware, for approx. 1
second.
0 0 G T - 3
V e r . 1 . 0 1
During this 1 second, the DSP is tested.
When the DSP test is successful, the unit starts the next test.
Otherwise, it will show an error message.
(2) Start from the "12.EXT OD CHECK" test.
Pressing buttons [PRE AMP/SP SIM] and [EQ], turn the power on.
Test Description
1. Display
This test first turns on all segments of LCD and LEDs.
2. LCD Contrast
2 . L C D
0 0 0 0 C o n t r a s t = 1 5
Turn the [VALUE] encoder dial and verify change in LCD
contrast.
1) Turn the [VALUE] encoder dial counterclockwise until
fifteen clicks are felt. The LCD will show below.
2 . L C D
0 0 0 0 C o n t r a s t =
2) Turn the [VALUE] encoder dial clockwise until fifteen
clicks are felt. The LCD will show below.
2 . L C D
0 0 0 0 C o n t r a s t = 1 5
The program proceeds to the next test.
3. Switch
S F X 0 # - - - - -
0 0 0 0 - - - - - -
Shown on the left of the LCD are the name of buttons and on
the right are the location of these buttons.
Initially these button locations are preceded by the symbol "-".
When this symbol changes to "*", press the corresponding
button and the symbol "#" is replaced by "*".
Wrong selection calls the error message.
0 C o n t r a s t
0 C o n t r a s t
0
0 C o n t r a s t
- - - -
- - - -
Feb. 1999
9