Forcing The System To Power-Off During Software Hang; Power-On And Power-Off Circuitry; Power-On; Power-Off - Sun Microsystems Sun Blade 150 Service Manual

C.8.1.3

Forcing the System to Power-Off During Software Hang

If the software is hung, the switch has a second mode. If the switch is held down for
4 seconds, the switch will turn the power supply off directly (independent of
software).
C.8.2

Power-On and Power-Off Circuitry

C.8.2.1

Power-On

Two conditions turn the system power on through the power on/off control circuitry
on the Sun Blade 150 motherboard:
The system was originally turned off and the front panel power on/off button is
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pushed.
The system was gracefully shutdown, and the alarm inside TOD M48T59 went
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off.
C.8.2.2

Power-Off

Two conditions turn off the system power through the power on/off control
circuitry on the Sun Blade 150 motherboard:
The system shuts down through the operating system: one general purpose
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output pin of the SouthBridge is activated to shut down the power supply.
When the system power was on, and front panel power on/off button is pressed
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for more than 4 seconds.
C.8.3

On-Board VRM

The CPU requires two different voltage sources, 3.3V with 5% tolerance and 1.7V
with 3% tolerance. The total estimated power consumption is around 19 Watts at 650
MHz speed. The 3.3V source for the processor is provided by the power supply and
the 1.7V source of the processor comes from an on-board voltage regulator. The
Raytheon RC5057 is the switcher control chip.
VRM ID codes from the CPU are not used. The 1.7 V code required for the processor
is hard set. Voltage changes are possible but require installation of special
header/jumper connections.
C-16 Sun Blade 150 Service Manual • June 2002