Service manual

4-8 AlphaServer 4000/4100 Service Manual
4.4 Power-Up/Down Sequence
The On/Off button can be controlled manually or remotely. The button is on
the OCP. Remote power control is provided though the remote I/O port
connected to the PCI. The power-up/down sequence flow is shown below.
Figure 4-4 Power Up/Down Sequence Flowchart
Apply AC
Power
Vaux on
Assert
DC_ENABLE_L
Power Supply
Starts
10 Second
Delay
Deassert
DC_ENABLE_L
Halt
12 Second
Delay
Deassert
DC_ENABLE_L
DCOK_SENSE
30 Second
Delay
Assert
DCOK_SENSE
On-Off
Button
On-Off
Button
Any
Faults
Voltages
OK
Fan/Temp
OK
On
Off
Yes
No
On
OffYe s
No
Yes
No
PKW-0402-95