User Guide

1.12 Power Supply 1 Hardware Overview
Satellite A40 Maintenance Manual (960-458) 1-33
1.12 Power Supply
The power supply supplies many different voltages to the system board and performs the following
functions:
1. Checks power input to determine:
• Whether the AC adaptor is connected to the computer.
• Whether the battery pack is installed and supplying power.
2. Checks power supply’s internal controls:
• Battery pack charging: start, stop and voltage supplied to the battery pack.
• Power supply system: Power supplied from a DC power source (AC adaptor).
• Faulty power supply: Executes forced shutdown if needed.
• Logic: Power supply to various circuits
• Charging current to PWM control IC for battery pack charging
3. Controls the following aspects of the logic system
• Power supply to gate arrays
• Power on/off
4. Indicates the following:
• DC IN (sets LED to orange or blue)
• Battery icon (sets LED to orange or blue)
• Faulty power supply by low battery
5. Interface for the following:
• BIOS via EC/KBC
• Function mode of power supply
6. Detects the following:
• Input voltage to logic system
• Input voltage, overvoltage and input/output to battery pack
• Battery pack’s internal temperature
• Input voltage to DC power supply (output from AC adaptor)
The power supply output rating is specified in Table 1-11.