220-1102 Question 153
Single answerUSB selective suspendA user with a Windows 11 laptop reports that a USB barcode scanner works normally for a few minutes, but after the laptop sits idle the scanner stops responding until it is unplugged and reconnected. The scanner works reliably on another PC. Device Manager shows no driver errors. You suspect Windows power management is placing the USB device into a low-power state. Which action is the BEST next step to resolve this issue while preserving the rest of the system's power-saving features?
- A
Disable USB selective suspend in the active Windows power plan
- B
Reinstall the laptop's video driver and reboot
- C
Format the laptop and perform a clean installation of Windows 11
- D
Disable Secure Boot in UEFI firmware
- E
Change the scanner's COM port number in Device Manager
Show answer and explanation
Correct answer: A
Explanation
The scenario matches a common Windows USB power-management issue: the device functions normally, then stops after idle time and resumes only after reconnection. USB selective suspend allows Windows to suspend individual USB devices to reduce power usage, especially on laptops. In troubleshooting, the best targeted step is to disable USB selective suspend in the active power plan rather than making unrelated driver, firmware, or OS changes. This preserves other sleep and battery-saving settings while addressing the likely cause. Microsoft documents USB selective suspend as part of Windows USB power management, and standard best practice is to make the least disruptive change that directly aligns with the symptoms.
- A. Correct.
Correct. USB selective suspend is a Windows power-management feature that can suspend an individual USB port/device to save power. If a USB peripheral stops responding after idle time and works again after reconnecting, disabling USB selective suspend in the active power plan is an appropriate troubleshooting step. This targets the likely cause without broadly disabling other power-saving features.
- B. Incorrect.
Incorrect. A video driver issue would not normally cause a USB barcode scanner to stop responding only after idle time. This is a plausible distractor because driver problems can cause intermittent device behavior, but the symptom pattern points to USB power management rather than graphics.
- C. Incorrect.
Incorrect. A clean OS installation is excessive and not the best next step. CompTIA-style troubleshooting emphasizes starting with the least invasive, most likely fix. Since the device works on another PC and there are no driver errors, adjusting USB power settings is more appropriate.
- D. Incorrect.
Incorrect. Secure Boot validates trusted boot components and does not control USB runtime power management in Windows. Someone might choose this because firmware settings can affect hardware behavior, but it is unrelated to selective suspend.
- E. Incorrect.
Incorrect. Some barcode scanners can enumerate as serial devices, but changing the COM port number would not address a pattern where the device fails only after the system is idle. The issue described is power-state related, not a port-number conflict.