Casio DT-940 Service Manual page 12

2.6 POWER ON BY SPECIAL KEY OPERATION
Ordinary, the unit starts up with the status of the last operation at the time of power off. (Resume function)
Turning the power on with pressing particular key executes particular operation.
2.6.1 SYSTEM MENU START-UP
Turning the power on with pressing S and . displays system menu on screen.
2.6.2 SYSTEM DUMPER START-UP
Turning the power on with pressing S and 1 starts up System dumper.
2.6.3 SYSTEM LOADER START-UP
Turning the power on with pressing S and 4 starts up System loader.
2.7 POWER SUPPLY CONTROL
ON and OFF of a power supply is controlled both by hardware and software viewpoint.
When the main battery is set up, a part of a main board is always is activated.
Therefore, main power turns on when conditions such as power on button or interrupt are detected.
2.7.1 POWER ON
Power is on in the following circumstances.
1) When the power button is pressed
2) When the initialize key (reset key) is pressed
3) Particular software setting
It is necessary to keep all the following conditions so that a power supply does turn on.
1) A main battery cover is closed.
* Actually, it means a main battery cover detection switch is on.
2) Confirmation of battery voltage
when lithium-ion battery are used: 2.8V or more
when two AA(LR6)size alkaline batteries are used: 2.1V or more
* When the voltage is low, the power turns on instantly and turns off immediately or it happens that
the power does not turn on at all.
Please confirm using fully charged lithium-ion battery pack or brand new AA (LR6)-size alkaline batteries.
3) There is no hardware defect such as over current.
* When over current flows caused by such as hardware defect, the power does not turn on
because the over current protection circuit turns the power off.
2.7.2 POWER OFF
Power is off under the following operation (circumstances).
1) When the power button is pressed
2) When a main battery cover is removed
* Actually, it means a main battery cover detection switch is off.
3) Confirmation of battery voltage
when lithium-ion battery are used: less than 2.8V
when two AA(LR6)size alkaline batteries are used: less than 2.1V
4) When the over current protection circuit detects the malfunction such as over current
5) No operation for specified period ( software setting:APO)
SYSTEM MENU g 2:MODE SET g 1:ENVIRONMENT g 1:APO TIME ( default value: 10 minutes )
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