Aloka ProSound Alpha 10, Service Manual, Page: 134 / 405

MN2-2008, Rev.2
SECTION 4 Principle of System Operation
4 - 101
Power Supply unit PSU-ALPHA10 Block diagram (M00951 and after)
In addition, the power on/off sequence is controlled by MPU on the Power I/O board follows;
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Power On sequence
1) When you turn on only the breaker switch, +5VSB and Ac output for DVD are
outputted.
2) When you turn on both beaker switch and Stand by switch, MPU on the Power I/O
board send Power-On signal to the CPU board.
3) After the CPU receive the Power-on signal, The CPU send ”PS_ON” signal to the MPU
on the Power I/O board.
4) After the MPU on the power I/O board receive the “PS_ON” signal, The MPU
send ”PWR_OK” signal to the Power supply unit. And then whole system start up.
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Power Off sequence
1) When you turn off the Stand by switch, MPU send “Power-off” signal to the operation
panel. And then the Operation panel send “PWR_OFF” signal to the CPU board via
USB.
2) After the CPU (Operation System) detects the “PWR_OFF” signal, System starts the
shutdown process.
For the fuse location, refer to
the circuit diagram.