Casio LK-90TV Service Manual page 22

2. AC adaptor check
1 Press "-" button.
3. Pedal check
1 Press "1" button.
2 "Sustain pedal": ON
3 "Sustain pedal": OFF
4. ROM check
1 Press "2" button.
5. MODEL check
1 Press "3" button.
6. ROM Ver. check
1 Press "3" button. (internal ROM)
2 Press "3" button. (extenal ROM)
7. RAM check
1 Press "+" button.
8. Sound check
1 Press the "4" button.
* When standing in the center, the tester hears the minimum test sound in an
equal volume from both right and left speakers.
2 Press the "5" button.
* When standing in the center, the tester hears the medium test sound in an
equal volume from both right and left speakers.
3 Press the "6" button.
* When standing in the center, the tester hears the maximum test sound in an
equal volume from both right and left speakers.
4 Press the "7" button.
* When standing in the center, the tester hears the maximum test sound fromthe
left speaker.
5 Press the "8" button.
* When standing in the center, the tester hears the maximum test sound from
the right speaker.
9. LCD check
1 Press the "STEP1" button.
* All dots and characters of LCD turn on.
* There is no lack of the dot and the charater.
— 20 —
Message on LCD
JOK
TCH
SUS
OOK
649
116
100
AOK
MIN
MID
MAX
L
R