Yamaha PortaTone PSR-270, Service Manual

Page: 17 / 33

PSR-270
17
1. TEST PROGRAM
A. PREPARATION
1) PA-3B (AC adaptor) is used when there is no specification. (PA-32,PA-3 are utilizable)
2) The volume is usually moved to the use position when no volume change is required.
3) Measuing instruments:
Frequency counter
Level meter (with a JIS-C filter)
Note: Use a stereo plug and connect the 33 Ω load at [PHONES/AUX OUT] jack.
4) Jigs:
Foot switch, MIDI cable
B. HOW TO ENTER THE TEST PROGRAM
While pressing the C2# ,F2 and G2# keys, turn on the [STAND BY/ON] switch on.
C. PROCEEDING THROUGH THE TEST PROGRAM
The LCD will display “TEST” when entering the test program.
To select the program number, use the [O/-] button.
To execute the test, press the [START/STOP] button.
To proceed to the next test, press the [START/STOP] button again.
D. TEST PROGRAM LIST
TEST
NO.
LCD (initial) Test Functions and Judgment Criteria
1 001:Version Displays Rom version
ROM(Program, Wave) versions are displayed alternately on the LCD.
2 002:Rom Chk1 Checks the ROM. The test result appears on the LCD.
3 003:Ram Chk1 Checks all the RAMs which are connected to the CPU.
The test result appears on the LCD.
11 011:TG1 Chk Outputs the sine wave by changing the channels in sequence from C2 to G4.
After autoscaling is finished, individual keys can be played. (If playing two or more keys
simulaneously, the final depressed key has priority to make a sound.)
13 013:Pit Chk Connect the frequency counter to the [PHONE/AUX OUT] jack.
Check that the 440 Hz +/- 1.76 Hz signal is output.
14 014:Output R
Connect the level meter (with a JIS-C filter) to the [PHONS/AUX OUT] jack. (33
Ω
load)
Set the [MASTER VOLUME] at maximum.
Check the output level (1kHz).
Phones L: Less than -50dBm
Phones R: -6.0dBm +/- 2dB
15 015:Output L Connect the level meter (with a JIS-C filter) to the [PHONS/AUX OUT] jack. (33 Ω load)
Set the [MASTER VOLUME] at maximum.
Check the output level (1kHz).
Phones L: -6.0dBm +/- 2dB
Phones R: Less than -50dBm
19 019:Noise
Connect the level meter (with a JIS-C filter) to the [PHONS/AUX OUT] jack. (33
Ω
load)
Set the [MASTER VOLUME] at maximum.
Phones L/R: Less than -80dBm