ADVANCED COMPUTER HARDWARE

• When a computer is booted, the basic input/output system performs a hardware check on the main components of the computer.
• Power-on self-test refers to the hardware check on the main components of a computer.
• If a device is malfunctioning, an error or a beep code alerts the technician of the problem.
• • To determine if POST is working properly, remove all the RAM modules from the computer and power it on. 
• What does CMOS stands for?

  Complementary Metal Oxide Semiconductor
• All motherboards need a BIOS to operate.
• BIOS is a ROM chip on the motherboard that contains a small program that controls the communication between the operating system and the hardware.
• True or False.

  Along with the POST, BIOS also identifies:

  • Which drives are available
  • Which drives are bootable
  • How the memory is configured and when it can be used
  • How PCIe and PCI expansion slots are configured
  • How SATA and USB ports are configured
  • Motherboard power management features

  True
• True or False. If the computer’s time and date are incorrect, it could indicate that the CMOS battery is bad or is getting very low.

  True
• What does UEFI stands for?

  Unified Extensible Firmware Interface
• UEFI can run on 32-bit and 64-bit systems, supports larger boot drives, and includes additional features such as secure boot.
• Passwords allow for different levels of access to the BIOS settings. 
• LoJack: This is a security feature that allows the owner to locate, lock, and delete the device.
• Trusted Platform Module: This is a chip designed to secure hardware by storing encryption keys, digital certificates, passwords, and data.
• Secure Boot is a UEFI security standard that ensures that a computer only boots an OS that is trusted by the motherboard manufacturer.
• In Full Access, all screens and settings are available, except the supervisor password setting.
• In Limited Access, changes can be made to certain settings only, for example, the time and date.
• In View Only Access, all screens are available, but no settings can be changed.
• In No Access, no access is provided to the BIOS setup utility.
• Modern BIOS chips are Electronically Erasable Programmable Read Only Memory, which can be upgraded by the user without opening the computer case.
• "Flashing the BIOS": Modern BIOS chips are Electronically Erasable Programmable Read Only Memory (EEPROM) which can be upgraded by the user without opening the computer case.
• To download a new BIOS, consult the manufacturer’s website and follow the recommended installation procedures.
• Voltage: The measure of work required to move a charge from one location to another.
• Voltage is measured in volts.
• Current: The measure of the amount of electrons moving through a circuit per second.
• Current is measured in amperes.
• Resistance: This refers to the opposition to the flow of current in a circuit.
• Resistance is measured in ohms.
• Power: The measure of the work required to move electrons through a circuit multiplied by the number of electrons going through the circuit per second.
• Power is measured in watts.
• This refers to a basic equation that expresses how voltage is equal to the current multiplied by the resistance: V = IR.

  Ohm's Law
• In an electrical system, power is equal to the voltage multiplied by the current: P = VI.
• On the back of some power supplies is a small switch called the voltage selector switch.
• The voltage selector switch sets the input voltage to the power supply to either...


  • 110V or 115V
  • 220V or 230V
• A power supply with voltage selector switch is called a dual voltage power supply.
• The correct voltage setting is determined by the country where the power supply is used.
• Blackout: Complete loss of AC power
• Brownout: Reduced voltage level of AC power that lasts for a period of time
• Noise: Interference from generators and lightning
• Spike: Sudden increase in voltage that lasts for a short period and exceeds 100 percent of the normal voltage on a line