Examkin

Soru

Zorluk: OrtaMotherboards Form Factors and Connectors

A technician is installing a replacement motherboard into a desktop tower and connecting the chassis front panel cabling to the system board headers. Which of the following statements accurately describe the installation requirements and operational characteristics of motherboard front panel headers? (Select TWO.)

  1. Power switch (PWR_SW) and reset switch (RESET_SW) connections operate as momentary contact switches and function properly regardless of positive or negative pin orientation.Cevap
  2. B
    The front panel reset switch (RESET_SW) header supplies continuous +12V DC power to retain system BIOS/UEFI settings when the power supply is turned off.
  3. Front panel status light-emitting diodes, such as the hard drive activity LED (HDD_LED) and power LED (PWR_LED), are polarity-sensitive and require correct positive (+) and negative (-) pin alignment to illuminate.Cevap
  4. D
    A standard 19-pin internal USB 3.0 front panel cable can plug directly into a legacy 9-pin USB 2.0 motherboard header without an adapter.

Cevap

Power switch and reset switch connections function regardless of pin polarity, while front panel status LEDs (HDD_LED and PWR_LED) require correct positive and negative pin alignment to illuminate.
Power and reset switches are simple momentary contact switches that briefly bridge two pins to send a signal to the power management controller, so their pin orientation (+/- polarity) does not affect operation. In contrast, LEDs (light-emitting diodes) are directional semiconductors that require current to flow from the positive (+) anode to the negative (-) cathode, making correct pin alignment mandatory for the lights to function.

Adım Adım Çözüm

1
Analyze the electrical characteristics of motherboard switch headers.
PWR_SW and RESET_SW use simple push-button momentary switches that short two pins together briefly to send a logic signal. Because no directional current flow is required for the switch mechanism, orientation does not matter.
Momentary switches complete an open circuit irrespective of polarity.
2
Analyze the electrical characteristics of motherboard LED headers.
HDD_LED and PWR_LED connect to light-emitting diodes. Diodes conduct current in only one direction (anode to cathode), so connecting them backwards prevents current flow and keeps the LED off.
Light-emitting diodes are polarity-sensitive semiconductors.
3
Evaluate the incorrect distractor statements regarding power delivery and USB header compatibility.
Reset headers do not deliver power to BIOS/UEFI chips, and 19-pin USB 3.0 front panel cables are physically incompatible with 9-pin USB 2.0 headers without an adapter.
Identifies wrong options based on incorrect motherboard pinout definitions and power roles.

Anahtar Kavram

Motherboard front panel header pinouts, polarity requirements for LEDs vs switches, and internal USB connector standards
Bu soruyu puanla

Konular

Motherboards Form Factors and Connectors

Bu konudan daha fazla soru