Basic display troubleshooting steps: When determining whether a PC display subsystem is functioning, which diagnostic questions should you ask or check first?

Introduction / Context:
Systematically narrowing down a “no video” complaint begins with simple, non-invasive checks. Power, basic POST beeps, screen controls, and physical signs of operation can quickly isolate whether the issue is the monitor, the GPU, the cable, or the system itself.

Given Data / Assumptions:

• Desktop or CRT-era monitor is suspected of not displaying an image.
• We have access to the system unit, the display, and front-panel controls.
• Initial checks precede swapping parts.

Concept / Approach:

Always start with fundamentals: verify monitor power and brightness/contrast settings, ensure signal cables are secure, listen for motherboard POST beeps, and look for any on-screen activity or status LEDs. On CRTs, static on the glass indicates high-voltage circuits are active; on LCDs, backlight and power LEDs indicate life. Combining all of these quick checks gives a clearer direction before deeper diagnostics.

Step-by-Step Solution:

Verification / Alternative check:

Swap with a known-good cable or monitor. If the system beeps normally and a second monitor works, the original monitor or cable is faulty. If no beeps and no video on either display, suspect the system or GPU.

Why Other Options Are Wrong:

• Individual checks alone can miss the root cause; the best first answer is to do all of them quickly.

Common Pitfalls:

Overlooking a dimmed backlight, muted brightness, or a loose cable; skipping POST beep observation; assuming the GPU is bad without testing.

Final Answer:

All of the above