220-1101 Question 424
Single answerIntermittent projector shutdownA conference room projector works normally for about 20 minutes and then shuts off without warning. The power LED changes to a warning color, and the projector can be turned back on only after it sits idle for several minutes. The issue occurs with multiple laptops and different video cables. The projector is ceiling-mounted near an air vent, and staff report that the air filter has not been cleaned in over a year. Which of the following is the MOST likely cause of the intermittent shutdown?
- A
The projector is overheating because airflow is restricted by dust buildup in the filter or vents
- B
The display resolution from the connected laptops is unsupported by the projector
- C
The HDMI cable is too long and is causing the projector to lose signal intermittently
- D
The projector lamp timer has reached its maintenance interval and is forcing a shutdown
Show answer and explanation
Correct answer: A
Explanation
The best answer is overheating due to restricted airflow. In CompTIA A+ Core 1 troubleshooting scenarios, intermittent shutdown after a predictable run time strongly suggests a heat-related problem, especially when the issue persists across multiple source devices and cables. Projectors commonly use thermal protection to shut down when internal temperatures exceed safe limits. Dust accumulation in filters and vents is a frequent real-world cause, particularly in ceiling-mounted installations that do not receive regular maintenance. Best practice is to inspect and clean the air filter and vents according to the manufacturer's maintenance guidance, confirm that intake and exhaust paths are not blocked, and verify the projector has adequate clearance and ambient cooling. If the issue continues after cleaning and ventilation checks, the technician would then evaluate the lamp, internal fans, and power subsystem.
- A. Correct.
Correct. A projector that runs for a period of time, shuts down, shows a warning LED, and only powers back on after cooling is demonstrating a classic overheating symptom. Dust-clogged intake filters or blocked vents reduce airflow, causing thermal protection circuitry to shut the unit down to prevent damage. In real-world support, cleaning the filter and ensuring proper ventilation are standard first steps.
- B. Incorrect.
Incorrect. An unsupported resolution typically causes display issues such as no image, distorted output, or an out-of-range message rather than a delayed shutdown after 20 minutes of use. Because the problem occurs after a warm-up period and with multiple source devices, the source resolution is not the most likely cause.
- C. Incorrect.
Incorrect. A poor or overly long HDMI cable can cause flickering, sparkles, signal dropouts, or no image, but it would not typically cause the projector itself to power off and require a cool-down period before restarting. This option is plausible because cable issues are common in conference rooms, but it does not match the shutdown-and-recovery pattern.
- D. Incorrect.
Incorrect. Lamp-hour maintenance warnings can indicate that the lamp should be replaced soon, and some projectors may restrict operation when lamp conditions are severe, but the described behavior more strongly matches thermal shutdown. A lamp timer alone does not usually cause the unit to operate normally for a fixed period and then require cooling before powering back on.