Maintenance and Troubleshooting Flashcards
7 cards from real CST practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Maintenance and Troubleshooting flashcards as text
A PTZ camera stops responding to control commands but still displays video. What is the most likely cause?
Answer: RS-485 communication failure
RS-485 is the standard control bus for PTZ cameras, and a failure on this bus would prevent control commands from reaching the camera while leaving video unaffected.
When performing preventive maintenance on outdoor cameras, which environmental factor most commonly degrades image quality over time?
Answer: Moisture and condensation inside the housing
Moisture infiltration into camera housings causes lens fogging, corrosion, and sensor damage, which are primary causes of outdoor camera degradation.
A technician notices that a camera's image appears washed out during daytime but looks normal at night. What should be checked first?
Answer: IR cut filter operation
A stuck or malfunctioning IR cut filter can cause images to appear washed out in daylight because the filter is not blocking infrared light from the sensor.
What tool is best suited for verifying that coaxial cable terminations have acceptable signal loss in an analog CCTV system?
Answer: Cable certifier or TDR
A TDR (Time Domain Reflectometer) or cable certifier can pinpoint faults, measure impedance mismatches, and verify signal loss in coaxial cabling.
A surveillance recorder's hard drive health check shows reallocated sector counts rising steadily. What action should be taken?
Answer: Schedule a drive replacement before failure occurs
Rising reallocated sector counts indicate impending hard drive failure; proactive replacement prevents data loss and system downtime.
After a power outage, an IP camera is unreachable on the network. The camera's link LED is solid green. What should the technician check next?
Answer: Verify the camera's IP address for a conflict or DHCP change
A solid link LED confirms physical connectivity, so the issue is likely an IP address conflict or a DHCP-assigned address change after the power cycle.
Which maintenance task helps prevent video loss caused by bit rot on surveillance hard drives?
Answer: Regularly running drive health diagnostics and replacing aging drives on schedule
Scheduled SMART diagnostics and timely drive replacement are the primary defenses against bit rot and unexpected drive failure in surveillance systems.