CompTIA Tech+ (FC0-U71)IT Concepts and TerminologyMedium
A user complains that their computer's clock frequently loses time, even after manually setting it. They also report that sometimes the system settings revert to defaults after a reboot. Which component is MOST likely failing?
- AThe RAM (Random Access Memory)
- BThe GPU (Graphics Processing Unit)
- CThe CMOS battery
- DThe CPU (Central Processing Unit)
Show answer & explanationAnswer & explanation
Correct answer: C. The CMOS battery
The CMOS battery powers the CMOS chip, which stores system BIOS/UEFI settings (like date, time, and boot order) when the computer is off. A failing CMOS battery would cause the clock to lose time and settings to revert to defaults upon reboot.
Why the other options are wrong
- A. Failing RAM would cause system instability, blue screens, or application crashes, not loss of time or BIOS settings.
- B. A failing GPU would primarily cause display issues, artifacts, or no video output.
- D. A failing CPU would likely cause system crashes, reboots, or failure to boot, not specifically clock/setting issues.
CMOS Battery
A small, coin-cell battery on the motherboard that powers the complementary metal-oxide-semiconductor (CMOS) chip, which stores BIOS/UEFI settings and keeps the real-time clock running when the computer is off.
- Maintains system date, time, and BIOS/UEFI configurations.
- Failure leads to loss of time and default settings upon reboot.
- Typically a CR2032 coin cell.
Memory trick: CMOS battery's dead, time's in dread, settings reset in your head.