Yamaha PORTATONE KB-280, Service Manual

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26
KB-280
TEST PROGRAM
Test No. LCD display Test descriptions, judging conditions, etc.
4 Test program list
1 Displays version of the ROM.
“
Prog
∗∗∗
” is displayed on the LCD.
∗∗∗
: Version
2 Checks the ROM connected to the CPU bus.
Make sure that “
Rom OK ” is displayed on the LCD.
3 Checks the RAM connected to the CPU bus.
Make sure that “
Ram OK ” is displayed on the LCD.
4 Checks the FROM connected to the CPU bus.
Make sure that “
FRom OK ” is displayed on the LCD.
5 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 sound or noise. When the auto-scaling is
finished, “
TG1 End ” will be shown. Press a key to play a sound. (Single note, the key pressed
first will be played)
6 Checks pitch accuracy.
Connect a 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)
7 Connect a level meter (with JIS-C filter) to the L/R of the [PHONES/OUTPUT] jack.
(33
Ω
of 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
8 Connect a level meter (with JIS-C filter) to the L/R of the [PHONES/OUTPUT] jack.
(33
Ω
of 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
1 Preparations
1) Use an AC adaptor PA-5D (PA-51).
2) Measuring device: Frequency counter, which can detect thousandth value or more, Level meter (with JIS-C filter)
Note: Use a stereo plug and connect a load resistor of 33
Ω
to the [PHONES/OUTPUT] jack for measurement unless
otherwise specified. Input impedance of the measuring device should be 1M
Ω
or more.
3) Jig: Foot switch (FC-4 or FC-5), MIDI cable
2 Starting up the Test Program
While holding down the keys [C2#], [F2], [G2#] simultaneously, press the [STANDBY / ON] switch.
∗
If the test number 47 “Factory Set” is executed, the data already set will be lost.
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 first character of the item for which the test results are OK.
If the results are NG, press the lowest key (white key C1) to return to the item selection display.
(dBu=dBm)
Version
001
Rom Chk1
002
Ram Chk1
003
FRomChk1
006
TG1 Chk
011
Pit Chk
013
Output R
014
Output L
015
F2
C2# G2#