CPI Troubleshooting & Maintenance 3 — Questions and Answers
Question 1: An HDMI cable run exceeds 25 feet and the image shows signal degradation. What is the most appropriate remedy?
- Replace HDMI with a standard RCA cable
- Install an active HDMI signal booster or fiber optic HDMI extender (Correct answer)
- Reduce display resolution to 480p
- Shorten the cable by folding it back on itself
Correct answer: Install an active HDMI signal booster or fiber optic HDMI extender
Active HDMI signal boosters or fiber optic HDMI cables are designed to maintain signal integrity over long distances beyond passive cable limits.
Question 2: A video wall shows image tearing where panels meet. What adjustment resolves this issue?
- Increasing the refresh rate on only one panel
- Synchronizing the refresh rates and enabling bezel correction on the video wall controller (Correct answer)
- Replacing the bezels with thinner ones
- Reducing the input resolution
Correct answer: Synchronizing the refresh rates and enabling bezel correction on the video wall controller
Bezel correction settings on the video wall controller compensate for the physical bezel width so the image appears continuous across all panels.
Question 3: During routine maintenance, a technician notices that a projector lamp has exceeded its rated hours. What action should be taken?
- Continue using the lamp until it fails completely
- Replace the lamp immediately and reset the lamp hour counter in the projector menu (Correct answer)
- Clean the lamp with compressed air to extend its life
- Reduce projector brightness to maximum lamp output
Correct answer: Replace the lamp immediately and reset the lamp hour counter in the projector menu
Operating a lamp beyond its rated hours risks sudden failure, reduced color accuracy, and potential damage; replacing it and resetting the counter ensures accurate tracking.
Question 4: A control system sends commands but the controlled device does not respond. After confirming the cable is good, what should be checked next?
- The room's ambient lighting level
- The baud rate, data bits, and parity settings between the control system and device (Correct answer)
- The display's aspect ratio setting
- The building's electrical panel
Correct answer: The baud rate, data bits, and parity settings between the control system and device
RS-232 and other serial communication protocols require matching baud rate, data bits, stop bits, and parity settings on both the sending and receiving devices.
Question 5: An outdoor LED display shows hot spots (brighter areas) on portions of the screen. What is a probable cause?
- Incorrect color temperature setting
- Failed or degraded LED modules or driver circuits in those areas (Correct answer)
- A loose mounting bolt on the frame
- Excessive ambient light on the screen
Correct answer: Failed or degraded LED modules or driver circuits in those areas
Hot spots on LED displays typically indicate failing LED modules or driver ICs that are operating outside normal parameters.
Question 6: What does an PoE (Power over Ethernet) injector allow an installer to do?
- Increase network data transfer speeds
- Power a network device through the Ethernet cable, eliminating a separate power supply (Correct answer)
- Convert Ethernet to fiber optic cable
- Boost Wi-Fi signal strength
Correct answer: Power a network device through the Ethernet cable, eliminating a separate power supply
A PoE injector adds power to an Ethernet cable, allowing compliant devices like IP cameras and digital signage players to receive both data and power from a single cable.
Question 7: After a power outage, a digital signage system does not automatically restart. What feature should be enabled to address this?
- UPS battery backup only
- Wake-on-LAN only
- 'Power on after power loss' or 'AC power recovery' setting in the device's BIOS/firmware (Correct answer)
- A manual scheduled reboot every morning
Correct answer: 'Power on after power loss' or 'AC power recovery' setting in the device's BIOS/firmware
The 'Power on after power loss' BIOS/firmware setting instructs the device to automatically power up when AC power is restored after an outage.
CPI Troubleshooting & Maintenance 3
An HDMI cable run exceeds 25 feet and the image shows signal degradation.
What is the most appropriate remedy?