Yamaha P-250 Service Manual page 37

No. LCD (initial)
32 032:To Host Chk
33 033:USB Chk
34 034:Keyboard Type Chk
35 035:Main Rom Chk2
36 036:Main Ram Chk2
37 037:FlashRom Chk2
38 038:WaveRom Chk2
39 039:EffectRam Chk2
40 040:Factory Set
41 041:Test Exit
Note: 0 dBm=0.775 V
Test Function and Judgment criteria
Short-circuit between pins 3 and 5, pins 6 and 8 of the [TO HOST] terminal and perform the test. Change the
[HOST SELECT] switch position according to the LCD indication and check that the following tone is output at
each postiion. (C3 at USB, C4 at PC-2 and C5 at MAC). Confirm that "To Host Chk OK" is displayed on the
LCD display.
Checks the USB jack.
Connect the [USB] jack and the personal computer with a USB cable, and then set the MIDI-USB driver of pc as
though. Set the [HOST SELECT] switch to the "USB" position and perform the test. Confirm that C4 sounds and
that "USB Chk OK" is displayed on the LCD.
Checks the keyboard type.
Perform the test. Confirm that the C4 sounds and that "KeyType OK (GHD)" is displayed on the LCD.
Checks all the ROMs that are connected to the CPU bus.
Outputs the C4 sine wave when the check result is OK and "Main Rom Chk2 OK" is displayed on the LCD
display.
Checks all the RAMs that are connected to the CPU bus.
Outputs the C4 sine wave when the check result is OK and "Main Ram Chk2 OK" is displayed on the LCD
display.
Checks all the flash memories that are connected to the CPU bus.
Outputs the C4 sine wave when the check result is OK and "Flash Chk2 OK" is displayed on the LCD display. It
takes about 50 seconds.
Checks the WAVE ROMs.
Outputs the C4 sine wave when the check result is OK and "Wave Rom Chk2 OK" is displayed on the LCD
display. It takes about 20 seconds.
Checks the Effect ROMs.
Outputs the C4 sine wave when the check result is OK and "Effect Ram Chk2 OK" is displayed on the LCD
display. It takes about 5 seconds.
When this test is performed, the factory preset data will be set in the Flash ROMs when the power is turned on the
next time. "Factory Set OK" is displayed on the LCD display. It takes about 15 seconds.
When the test is executed, the test program will exit and the play mode will be set.
P-250
37