Test Your Device
Home › Device Checkups › New Monitor Checkup

Testing a New Monitor Inside the Return Window

By Jayadeep · Updated August 2026 · About 8 minutes

Six checks to run in the first few days, while returning the monitor is still a decision rather than a negotiation.

There is a specific window in which a faulty monitor is easy to deal with, and it is much shorter than most people assume. Inside the retailer's return period you can usually send it back for a replacement or a refund with no argument about thresholds. Outside it you are dealing with the manufacturer's warranty, which is where pixel policies apply — published rules specifying how many defective pixels a panel must have before it qualifies, with different thresholds for bright and dark defects and for different panel grades.

The gap between those two regimes is what makes early testing worth doing. A panel with two dead pixels is often an easy return on day three and an unwinnable warranty claim on day sixty, because a small number of dark defects falls below most manufacturers' replacement thresholds. Nothing about the panel changed; only your options did.

The second reason is that the most common new-monitor complaint is not a defect at all. A high-refresh panel plugged in and left at the operating system's default frequently runs at 60Hz, and the display cable that came in the box is not always rated for the resolution and refresh rate combination you bought the monitor for. Both look like disappointing hardware and are actually a setting and a cable.

The checklist

Tick each step as you go. Do the whole list in one sitting if you can, in a dimly lit room, while the return window is still comfortably open.

0 of 6 done

  1. Step through white, black, red, green and blue at full screen in a dimly lit room. Look carefully at the whole panel, including the corners.

    Open the Dead Pixel / Screen →

    Pass: No fixed dots on any colour field.

    Fail: Any dot that stays in the same place as the background colour changes.

    If it fails: Dead pixel vs stuck pixel — Classify the defect before contacting the retailer — it affects your argument.

  2. Display full black in a dark room and let your eyes adjust for a minute. Some corner glow is normal on IPS panels.

    Open the Black Screen →

    Pass: Even darkness with at most slight corner glow.

    Fail: Bright patches or clouding along an edge that remain visible in ordinary dark content.

    If it fails: Testing a new monitor — Judge whether the bleed is within normal variation or worth returning.

  3. Red, then green, then blue. Each drives one subpixel channel, which is how a partially stuck pixel reveals itself.

    Open the Red Screen →

    Pass: Uniform colour with no dark or bright specks on any of the three.

    Fail: A speck visible on one primary but not the others — a single failed subpixel.

    If it fails: Check a monitor for dead pixels — Confirm the finding and record it properly for a return.

  4. Close other demanding applications, then run the test and compare the result with the panel's rating.

    Open the Refresh Rate Test →

    Pass: A measured rate at or near the monitor's advertised maximum.

    Fail: A measured rate well below the rating — most often 60Hz on a high-refresh panel.

    If it fails: Monitor stuck at 60Hz — Fix the display setting or identify the cable that is capping you.

  5. Read the reported resolution and pixel ratio. A cable that cannot carry your resolution at your refresh rate will silently force one of them down.

    Open the Screen Resolution & Info →

    Pass: Native resolution reported, at the refresh rate you selected.

    Fail: A lower resolution than the panel's native specification.

    If it fails: Find your screen resolution — Understand what is being reported and where the bottleneck is.

  6. Refresh rate is what the panel can show; this is what your machine delivers. Both need to be right for motion to look smooth.

    Open the FPS Test →

    Pass: Frame rate stable and close to the refresh rate you measured.

    Fail: Frame rate well below the panel's refresh rate, or visibly unstable.

    If it fails: Refresh rate vs frame rate — Separate a monitor problem from a graphics performance problem.

More tests worth running here

Not essential to the checklist above, but relevant to this situation and quick to add.

White ScreenGreen ScreenBlue ScreenColor Blindness Test

Frequently Asked Questions

How soon should I test a new monitor?

As soon as it is set up, and certainly within the retailer's return period. Return windows are typically far shorter than the warranty and far easier to use, because they generally do not require the panel to exceed a defect threshold. Testing on day two gives you options that testing on day sixty does not.

How many dead pixels qualify for a replacement?

There is no universal number — it is set by each manufacturer's published pixel policy and varies with panel grade and with whether the defect is bright or dark. Bright stuck pixels typically qualify at lower counts than dark dead ones. Look up the policy for your specific model and manufacturer before starting a claim, and prefer a retailer return if you are still inside that window.

Is backlight bleed grounds for a return?

It depends on severity and on the retailer. A degree of corner glow is normal on edge-lit IPS panels and is generally not accepted as a defect. Bleed that is visible during ordinary dark content, rather than only on a full black field in a dark room, is a much stronger case.

My 144Hz monitor is only measuring 60Hz. Is it faulty?

Almost certainly not. The overwhelmingly common cause is that the operating system is still driving the panel at its default rate — change it in your display settings. The second most common cause is a cable or port that cannot carry your resolution at that refresh rate. Check both before assuming the panel is at fault.

Should I test with the cable that came in the box?

Test with it, but do not assume it is sufficient. Bundled cables are not always rated for the maximum resolution and refresh rate the monitor supports. If you cannot reach the advertised refresh rate, swapping to a cable explicitly rated for that combination is the first thing to try.

Is a stuck pixel the same as a dead one?

No. A dead pixel receives no power and stays black on every background. A stuck pixel is powered but frozen on a single colour, so it appears as a bright dot. The distinction matters commercially, because bright defects usually qualify for replacement at lower counts than dark ones.

Other checkups

The screen tests here only fill your display with colour fields and count frames the browser presents. No data about your monitor is collected or sent anywhere. See how we validate these tests.

Found an error on this page, or a result that does not match your hardware? Tell us and we will correct it.