A faulty picture has three possible homes: graphics card, cable, or monitor. One screenshot and one cable wiggle separate them before you spend a rupee.
Screen faults cause more wrong purchases than almost any other symptom, because a dying GPU, a damaged cable and a failing panel can draw nearly identical pictures. Stop guessing: two free tests divide the suspects cleanly. The screenshot test tells you whether the graphics card created the fault. The wiggle and swap test then separates cable from panel. This guide walks both tests, then reads the common pictures — vertical lines, colour casts, flicker, random artefacts — and says plainly which faults no setting will ever fix.
👆 Example results. The screenshot is captured from the GPU frame buffer — it shows only what the GPU made.
When the fault is on screen, press Windows + Shift + S (or Print Screen), capture the faulty area, and look at the captured image — zoom in on it or view it on your phone.
This works because a screenshot copies the image from the graphics card's memory before it travels down the cable. Whatever the card made is in the file; whatever the cable or panel adds is not.
With the GPU cleared, three quick moves finish the job:
A green or pink colour cast that vanishes when the connector is reseated is the classic bent-pin or half-seated cable. A fault on every input of the monitor, with every cable, is the panel or its board — that is a repair-shop or replace decision, not a settings problem.
Each picture shape leans toward a cause. Straight vertical or horizontal lines fixed in one place on every screen usually mean the LCD panel or its internal ribbon connections. Random blocks, spikes, snow or checkerboard artefacts that worsen in games point at the GPU — failing video memory draws exactly that garbage, and it will show in screenshots. Flicker splits by rhythm: a steady shimmer is often a wrong refresh rate or a failing backlight, while flicker that follows cable movement is the cable. A line that changes when you press the screen bezel is panel connection damage. None of these readings is a verdict by itself — they tell you which confirming test to run from the sections above.
Before condemning a card, remove the software suspect. Artefacts or a wrong resolution that began right after a driver update, faults that appear only inside Windows and never on the BIOS screen or boot logo, and a picture that is perfect in Safe Mode all point at the driver rather than the silicon. Roll back the driver, or clean-install the version from the card maker's site. The mirror rule also holds: a fault visible on the very first BIOS screen, before any driver loads, cannot be a driver problem — that is hardware (GPU, cable or panel) and the split tests decide which.
Watch the split tests done live in the video — screenshot proof, cable wiggle and panel faults on real screens, so you can repeat them at home.
▶️ Watch Full VideoA fixed straight line in one position on every screen, including the BIOS screen, is almost always the panel or its internal connections. Confirm with the screenshot test — a panel line never appears inside a screenshot.
Unlikely — a fault in one program is that program, its settings or the driver path it uses. Test the desktop and another game; if they are clean, adjust the game's refresh or sync settings and update the graphics driver before suspecting hardware.
Probably nothing broke — a half-seated HDMI or DisplayPort connector loses colour depth and can add a green or pink cast. Reseat both ends firmly, and try the other port. Moving desks damages more cables than any other event.