Operational Check By Utilizing The Test Program - Yamaha FB-01 Service Manual

■ OPERATIONAL CHECK BY UTILIZING THE TEST PROGRAM
Test Mode Entry
Before executing the Test Mode or a repair save the user in¬
formation, all data stored in the S-RAM will be erased when
the Test Mode is activated.
Depress and hold the "SYSTEM SET UP", "INST SELECT"
and "DATA ENTRY - 1/NO". Switches on the front panel
while turn ON the POWER switch, and the test program,
starts operating. Test data is written in the S-RAM memory
area which is from 8000 to BFFFH (indicated as FFFFH).
When this process is complete "S-RAM WRITE END" is
displayed, which means that the data for the backup circuit
check has been written in the S-RAM.
TEST MENU MODE
Pressing the "VOICE SELECT" switch after the "S-RAM
WRITE END" message is displayed sets the TEST menu
mode. The "VOICE SELECT" switch is also used when set¬
ting the mode back to the TEST menu mode from other TEST
mode routines. Once the mode is set to the TEST menu, the
message " = = IFB TEST = =" will be displayed on LCD.
Battery-backup function & S-RAM check
1. Turn ON the battery backup switch.
2. Press the proper switch to set to TEST MODE.
3. If the S-RAM doesn't have the test data written in, writing
of the prescribed data starts automatically.
4. Upon completion of writing the message "S-RAM WRITE
END" i^ displayed. (Press the "VOICE SELECT" key to
return to the menu.)
5. Turn OFF the power and wait for two hours.
6
. Turn ON the power again, set to the TEST mode and check
that "S-RAM CHECK OK!" message is displayed. When
turning ON the power, be sure to start in the TEST mode.
If having started in the NORMAL mode, repeat this pro¬
cess from above step 2.
If the data in S-RAM has been erased, the prescribed data
is automatically written in. However, if "S-RAM WRITE
END" is not displayed after the comparative check, it
means that the S-RAM related part is defective and the
check after this will become ineffective.
LCD Check
1. Press the proper switches to enter the TEST mode.
2. Press the "VOICE-SEL" switch to select the TEST menu
mode the following message should be displayed " = = IFS
TEST = =".
3. Press the "SYSTEM" switch to select the LCD TEST
mode.
4. Check to make sure that LCD displayed characters as
shown in Table 1 which will increment from COHto FFh
During each increment 16 characters are displayed at a
time.
5. To stop the sequence and display routine of 16 characters
press the VOICE FUNC switch, and the display will stop
temporarily.
6
.To exit the LCD display routine, press the SYSTEM switch.
7. As a final step, check to make sure that the CHARACTER
GENERATE RAM display appears as shown in the figure.
8
. Also, check that the color, contrast, visual angle and visual
angle range are appropriate.
CPP TIMER Test
1. Press the specified switch to increment to the TEST menu
mode.
2. Press "- 1/NO" switch to advance to the TIMER TEST
PROGRAM.
3. Check to make sure that the "TIMER OK!" message is
displayed.
MIDI Function
1. Prepare two FB-01 standard units (Standard unit is a
FB-01 unit that is known to be functioning correctly).
2. Connect them as shown in Fig.2 by using the MIDI cable
included in the package.
3. Press the specified switch to increment to the TEST menu
mode.
4. Press the INST SEL switches of the standard units (j) and
(2) in Fig.2 to advance to the MIDI TEST mode. (UART
MIDI CHECK)
5. Press the INST SEL switch of the unit being tested to ad¬
vance to the MIDI TEST mode.
6
. Check to make sure that after a few seconds, the "MIDI
OK!" message is displayed on all three units.
AMP Characteristics
1. Terminate both L and R terminals with 47KQ resistors.
2. Press the specified switch to advance to the TEST menu
mode.
3. Press the + 1/Yes switch to run the OPP SOUND CHECK
PROGRAM.
4. Press the - 1/No switch to initiate the output of a 1kHz
TEST signal.
5. Connect a frequency counter to either L or R terminal and
check that frequency is within 1000Hz ± 1Hz.
6
. Using an AC voltmeter (level meter Model M-1 74A of NF
make or equivalent), check to make sure that the FLAT
characteristic is within ± 0.3dB of the specified value and
that the level difference between L and R is within 0.6.dB.
7. Using an oscilloscope, check to make sure that the
waveform is not distorted or clipped from.
8
. Using a distortion meter, check to make sure that the
distortion factor is within 0.5%.
9. Press SYSTEM, INST SEL, -1/NO, + 1/YES, INST
ASSIGN and INST FUNC switches one by one continuous¬
ly and check that the reading of the AC voltmeter is within
± 0.3% of the specified value.
10. Turn the power ON and OFF, and check that the AC
voltmeter reading is less than lOmV then.
11. Check to make sure that the residual noise is less than
0.5mV in the TEST menu mode.
12. With the same settings as specified in step No.6, add a
IkQ to the load resistor and check that the output level
changes to one half the original level.
(Fig. 1)