Yamaha PSR-S550 Service Manual page 34

PSR-S550/PSR-S550B
D. Test Item List
TEST
LCD Display
No.
3 003 Ram Chk1
4 004 Flash Rom Chk1
5 005 Wave Rom Chk1
7 007 TG1 Chk
8 008 Pit Chk
--
9 009 Output R
10 010 Output L
18 018 SW Chk
19 019 All LED Chk
20 020 Red LED Chk
21 021 Green LED Chk
22 022 LCD On
23 023 LCD Off
34
Test Descriptions, Judgment Criteria
Checks the RAM that is connected to the CPU bus.
The test results appear on the LCD. Check that the LCD displays "Ram OK".
(OK:"Ram OK", NG:"Ram NG")
Checks the flash ROM that is connected to CPU bus.
The check result appears on the LCD. Check that the LCD displays "Flash Ram OK".
(OK:"Flash Rom OK", NG:"Flash Rom NG")
Checks the wave ROM that is connected to CPU bus.
The check result appears on the LCD. Check that the LCD displays "Wave OK".
(OK:"Wave OK", NG:"Wave NG")
Outputs the sine wave by changing the channels in sequence from C2 to G4.[32 notes]
Check the sound by hearing that there is no noise or abnormal sound.
After auto-scaling is finished, individual keys can be played. (If playing two or more
keys simultaneously, the first pressed key has priority to make a sound.)
Connect the frequency counter to the [PHONES/OUTPUT] jack L or R.
Check that the correct signal is produced. (441.0 Hz ± 0.2 Hz)
Volume Decrescence Check
Connect the level meter(with a JIS-C filter) to the [PHONES/OUTPUT] jack. (33Ω load)
Set the [MASTER VOLUME] at minimum and check the output level.
PHONES L : less than -70.0 dBu PHONES R : -70.0 dBu (dBu=dBm)
Connect the level meter (with a JIS-C filter) to the [PHONES/OUTPUT] jack. (33Ω load)
Set the [MASTER VOLUME] at maximum and check the output level (1 kHz sine
wave, PAN=R).
PHONES L : less than -45.0 dBu PHONES R : -5.5 dBu ± 2 dB
Connect the level meter (with a JIS-C filter) to the [PHONES/OUTPUT] jack. (33Ω load)
Set the [MASTER VOLUME] at maximum and check the output level (1 kHz sine
wave, PAN=L).
PHONES L : -5.5 dBu ± 2 dB
Checks the switches on the panel.
Press the switches on the LCD as instructed. A pre-assigned note is output when the
switch is pressed. A rotary encoder is clockwise set up to UP and is counterclockwise
set to DOWN. (See P.36 "Table 1".)
The check result appears on the LCD when all the switches are pressed as instructed.
Check that "SW OK" is displayed. Also, check that no key stick is existed.
(OK:"SW OK", NG:"SW NG", When multiple switches are pressed at the same
time:"Over Two")
Check that all the LEDs on the panel are on.
Check that all the red LEDs on the panel are on.
Check that all the green LEDs on the panel are on.
Check that all LCD dots are on. (The whole screen becomes white.)
Check that all LCD dots are off. (The whole screen becomes blue.)
PHONES R : less than -45.0 dBu