Yamaha KB-180, Service Manual

Page: 26 / 46

KB-180/SKB-180
26
TEST PROGRAM
1 Preparations
1) Use an AC adaptor PA-5D.
2) Measuring device: Frequency counter, which can detect thousandth value or more, Level meter (with JIS-C fi lter), Oscilloscope
Note: Use a stereo plug and connect a load resistor of 33 Ω to the [PHONES/OUTPUT] jack for measurement unless otherwise
speci fi ed. Input impedance of the measuring device should be 1 M Ω or more.
3) Jig: Foot switch (FC-4 or FC-5), MIDI cable, EXP pedal
2 Starting up the test program
While holding down the keys [C#2], [F2] and [G#2] simultaneously, press the [STANDBY/ON] switch.
F2
C#2 G#2
3 Test procedure
1) When the test program is started, “
TEST
” will be displayed on the LCD.
2) Press the [-] or [+] button of the number buttons to select a test program item.
3) Press the [START/STOP] button to execute the test.
If the result is OK or test item is completed,
press the [START/STOP] button again to return to the item selection display.
Press the [-] or [+] button of the number buttons to select the next test item.
A cursor (“_”) is shown below the
fi rst character of the item for which the test results are OK.
If the result is NG,
press the lowest key (white key C1) to return to the item selection display.
4 Test program list (dBu=dBm)
TEST No LCD display Test descriptions, judging conditions, etc.
1 Version
001
Displays version of the ROM.
“
Prog
∗∗∗
” is displayed on the LCD.
∗∗∗
: Version
2 Rom Chk1
002 Checks the ROM connected to the CPU bus.
Make sure that “
Rom OK ” is displayed on the LCD.
3 Ram Chk1
003
Checks the RAM connected to the CPU bus.
Make sure that “
Ram OK ” is displayed on the LCD.
6 FRomChk1
006
Checks the FROM connected to the CPU bus.
Make sure that “
FRom OK
” is displayed on the LCD.
11 TG1 Chk
011
Plays each key automatically in the order of scale (auto-scaling). (32 notes from C2 to G4 will be played.)
Make sure that there is no abnormal sounds or noise. When the auto-scaling is
fi nished, “
TG1 End
”
will be shown. Press a key to play a sound. (Single note, the key pressed fi rst will be played)
13 Pit Chk
013
Checks pitch accuracy.
Connect the frequency counter to the [PHONES/OUTPUT] jack. (Either L or R)
Make sure that the correct signal is output. (440.14 Hz ± 0.22 Hz)
14 Output R
014
Connect the level meter (with JIS-C fi lter) to the L/R of the [PHONES/OUTPUT] jack.
(33 Ω load)
Set the [MASTER VOLUME] to the maximum level and check the output level.
· PHONES L: -55.0 dBu or less
· PHONES R: -4.5 dBu ± 2 dB
15 Output L
015 Connect the level meter (with JIS-C fi lter) to the L/R of the [PHONES/OUTPUT] jack.
(33 Ω load)
Set the [MASTER VOLUME] to the maximum level and check the output level.
· PHONES L: -4.5 dBu ± 2 dB
· PHONES R: -55.0 dBu or less
* If the test number 47 “Factory Set” is executed, the data already set will be lost.