Yamaha 01x, Service Manual

Page: 69 / 153

69
O1X
4. Description of Check Items
4.1 FLASH ROM/SDRAM function check ....
(01) CPU MEMORY
(1) Outline
The writing and reading functions are checked on SDRAM and
FLASH ROM and the result is displayed on LCD.
●
Writing and reading test of SDRAM
Execute the writing and reading test for the specified area
of SDRAM. Write the data of the data bus to the specified
address by changing 1 bit each and check if it is written and
read correctly. Also, write the data of the address bus by
changing 1 bit each and check if it is read correctly.
●
Signature ID reading test of FLASH ROM
Issue the command sequence to read the signature ID of
FLASH ROM. If the ID is obtained correctly, it proves that
FLASH ROM is capable of writing and reading.
(2) Execution method in the normal state
When operating normally, the screen returns to the execution
select screen and "O" is displayed in the check item space.
(3) Execution method in the faulty state
When an error is indicated on the display, press [KNOB-8] to
end testing.
The screen returns to the execution select screen and "X" is
displayed in the check item space.
01:CPU MEMORY
ERROR:xxxxxxxxxx EXIT
(4) Item description and error message
1: SDRAM to SDRAM read and write function check (to
check if what is written in SDRAM can be read)
Error message: ERROR:SDRAM
2: FLASH ROM to FLASH ROM read and write function
check (to check if the manufacturer code of the device can
be read)
Error message: ERROR: FLASH WRITE
(5) Check point when judged as NG
The devices that can be diagnosed by this check are as follows.
Circuit board Device name Function
DM CPU (IC101) Control of SDRAM, FLASH ROM
DM SDRAM (IC116) RAM for program execution
DM FLASH ROM (IC117) ROM for program memory
4.2 Switch input check .....
(02) SWITCH
(1) Outline
The key condition of all switches is read.
02:SWITCH
PUSH ->xxxxxxxxx
Have the function name of the switch to be checked flashed on
the LCD and press the applicable switch. If a judgment is made
that a switch other than the applicable one is turned on or a
multiple number of switches are turned on simultaneously, "NG"
is displayed beside each switch name and each "NG" remains
on until only the correct switch is turned on. When the key
condition can be read properly and the switch is judged as being
turned off, the function name of the next switch to be checked
is displayed (flashing).
(2) Execution method in the normal state
Press all the switches starting from the key located at the upper
left of the panel toward the one at the lower right. Then connect
the foot switch to the FOOT SWITCH 1 terminal and FOOT
SWITCH 2 terminal and depress it.
When all switches are read in the proper order, the screen returns
to the execution select screen and "O" is displayed in the check
item space.
(3) Execution method in the faulty state
To terminate before the end due to an error, press the [CURSOR
＜ ] and [CURSOR ＞ ] keys. The screen returns to the execution
select screen and "X" is displayed in the check item space.
(4) Item description and error message
None
(5) Check point when judged as NG
The devices that can be diagnosed by this check are as follows.
Circuit board Device name Function
DM CPU (IC101) Control of CI-SUB
DM CI-SUB (IC403) Gate array for control of SW matrix, etc.
DM JK (JK301) FOOT SWITCH1
DM JK (JK302) FOOT SWITCH2
PN SW (SW***) SW
RE SW (SW***) SW