41
PSR-E433/PSR-I455
START-UP SEQUENCE (PSR-E433, PSR-I455)
Meaning of marks
Test Program ?
Sound can be played by PAD/MIDI
The keyboard is defective if it is
impossible to enter the test
Indication
RAM Process
Other
Normal Process
Description of
NG judgment
Description of
operation
Opening indication
("YAMAHA")
Main screen
("GrandPno" (PSR-E433))
("Harmum1" (PSR-I455))
indication
Test Program
("TEST") indication
If it boots but does not run up to here,
the PROGRAM ROM (IC101)/SDRAM
(IC131) usually is not the problem.
SWL01U (IC001)/DataFlash (IC121) is
defective.
If keys produce sound, but
nothing is displayed, the LCD
IC or the wiring around the
LCD is defective.
Enabling MIDI (Serial)
Starts OS
Starts initialization task
Non-backup parameter
setup
Backup parameter setup
Completes initialization task
Judges test program after waiting
for 100 ms
MAIN
Various task initialization
Interrupt vector setup
SW/LED initialization
drive signal output
Serial driver initialization
Timer driver initialization
ADSP initialization
Cancels MUTE (DAC)
Cancels MUTE (AMP)
Timer interrupt setup
Interrupt priority,
edge/level setup
Backup RAM clear
Judgment
Test program
Normal operation
Cancels interrupt
Boot
Power On
YES
NO
When the power button is
pressed and released, the
backlight turns off and the LED
does not light at all.
Check the power supply.
If there is no problem with the
power supply, replace the
DMLCD circuit board.
SWL01U (IC001) 36Pin
PF0 L
→
HLHL
･･･
SWL01U (IC001) 50Pin
PG2 H
→
HLHL
･･･
SWL01U (IC001) 164Pin
PF3 L
→
H
SWL01U (IC001) 165Pin
PJ5 L
→
H
36pin
LCD EN
50pin
LCD RS
500
μ
sec
230nsec
LCD display refresh timing after
exiting interrupt
The signal does not continuously
change, and if the screen refreshing
stops the signal does not change.
Refreshing LCD display contents
*
*
