220-1101 Question 262
Single answerMotherboard connector typesA technician is replacing a failed desktop motherboard and is reconnecting the front-panel case wiring. The customer says the power button worked before the failure, but after the replacement, pressing the case power button does nothing. The technician confirms the 24-pin ATX and 8-pin CPU power connectors are properly attached, and the power supply passes testing. Which motherboard connector should the technician verify first to restore normal power-button operation?
- A
The front-panel header (system panel connector) for the power switch leads
- B
The SATA data connector for the system drive
- C
The USB 3.0 internal header for the front USB ports
- D
The 4-pin PWM fan header for the CPU cooler
Show answer and explanation
Correct answer: A
Explanation
This question tests practical identification of motherboard connector types in a repair scenario. On ATX motherboards, the case power switch connects to the front-panel header, which also commonly includes pins for reset switch, power LED, and drive activity LED. When a motherboard is replaced, these small individual leads are easy to misplace because pin layouts vary by manufacturer and model. Best practice is to consult the motherboard manual or board silkscreen for the exact front-panel pinout before reconnecting case wiring. By contrast, SATA, USB, and fan headers serve different functions and do not carry the power-button signal used to initiate startup.
- A. Correct.
Correct. The case power button connects to the motherboard's front-panel header, often labeled F_PANEL, JFP1, or system panel. If the power switch leads are connected to the wrong pins, reversed on a non-polarized pair location, or omitted entirely, pressing the power button will not signal the board to start. Verifying this header is the first step when the PSU and main board power connectors are already confirmed.
- B. Incorrect.
Incorrect. A SATA data connector links a storage device to the motherboard for data transfer. Even if the SATA cable were disconnected, the system should still respond to the power button and begin POST. This option reflects a common misconception that all internal connectors affect initial power-on behavior.
- C. Incorrect.
Incorrect. The USB 3.0 internal header supports the front-panel USB ports, not the case power switch. A missing or misconnected USB header may disable front USB functionality, but it would not normally prevent the motherboard from responding to the power button.
- D. Incorrect.
Incorrect. The CPU fan header powers and monitors the CPU cooler fan. Some systems may warn or shut down quickly if no CPU fan is detected, but that happens after startup is initiated. It does not normally prevent the power switch signal from reaching the motherboard.