Dell UltraSharp U2724DE: Uneven Brightness or Visible Backlight Bleed
Uneven Brightness or Visible Backlight Bleed on the Dell UltraSharp U2724DE: what we found on our own £549 unit, the checks that resolve it, and when it is a warranty case rather than a setting. Corne...
Daniel Reyes
What you are seeing
Dell UltraSharp U2724DE, refresh 120Hz. Uneven Brightness or Visible Backlight Bleed is the fault being chased here, on a unit bought and tested rather than loaned. It is genuinely good at iPS Black doubles the contrast of a normal IPS without OLED burn-in risk, and the thing that repeatedly cost it marks was not fast enough for competitive gaming.
Corners of the screen glow on dark content, or one edge is noticeably brighter than the rest of the panel. That is the behaviour; what follows is how it tends to present on this particular Dell, and what to rule out first.
Worth knowing: Work through these in order. The first two resolve the majority of cases and neither risks your data.
The quick checks
| Check | Why it matters |
|---|---|
| Is it reproducible? | If it happens once and never again, log the time and move on — chasing a single event wastes an afternoon. |
| Has anything changed? | A firmware update, a new app, a new accessory. The cause is almost always the most recent change. |
| Does it happen on a fresh restart? | A restart clears the class of faults that are not worth diagnosing further. |
| Is it under warranty? | The Dell warranty makes some of the steps below unnecessary — check before you start pulling things apart. |
Step by step
- Photograph a full black screen in a dark room at a fixed exposure, so you are judging against a record rather than memory.
- Let the panel warm up for thirty minutes before assessing, as bleed commonly reduces as the panel reaches temperature.
- Reduce brightness to a realistic working level; bleed measured at 100 percent is not what you will live with.
- Check the panel is not being squeezed by an over-tightened VESA mount or a badly seated stand.
- Compare against the maker’s published uniformity tolerance, which is usually stated and usually generous.
- Assess against real content rather than a black test pattern, which is the worst case rather than the normal case.
If none of that worked
Bleed that is visible on ordinary content at normal brightness is worth a return within the retailer window, whatever the tolerance says.
How to stop it recurring
Inspect within the return period. Panel uniformity varies unit to unit and almost never worsens after the first weeks.
Why it happens
In our experience this is rarely a single fault. The common pattern is an accumulation: a background process that was fine on its own, a setting changed months ago, and — on the Dell UltraSharp U2724DE specifically — 350 nits is dim in a bright room, which narrows the margin before anything else goes wrong. That is why the steps above start with the cheap reversible checks: on a Dell device the expensive diagnosis is almost never the one you needed.
Things to avoid
- Do not change several settings at once — you will fix it without ever learning what caused it, and it will come back
- Do not install a third-party "optimiser" — on modern hardware these do nothing the operating system is not already doing
- Do not factory reset before backing up, and do not restore that backup immediately afterwards; if the cause is in the backup you have simply reinstalled it
- Do not leave it on charge overnight as a workaround for 350 nits is dim in a bright room — it treats the symptom and shortens the life of the cell
- Do not open the case while it is under Dell warranty; that is the one step you cannot undo
When it is not fixable at home
If the behaviour persists after a factory reset, it is worth raising with Dell under warranty rather than working around it. Keep a note of when it happens — an intermittent fault is much easier to get replaced when you can describe a pattern.
Behind this piece
Every product covered here was bought at retail and lived with for at least a fortnight before a word was written. Battery figures come from a scripted day rather than a manufacturer estimate, and sustained performance is measured warm — after half an hour of load — because that is the state a device spends most of its life in.
Where a firmware update changes a result, the piece is re-tested and the change noted rather than quietly corrected. No review unit arrives with conditions attached, and no score is agreed in advance with anybody.
Where to go next
If you are weighing this against the rest of the monitors we have covered, the category archive lists every review in date order. The closest comparisons we have published are Gigabyte M27Q P Review: Very Good, With Caveats and Gigabyte M27Q P vs AOC 24G2SPU: Is the 2023 Model Worth the Change?.
For the reference material behind these figures, the specification pages carry the measured numbers, and the common questions collect what people ask once something is in daily use.
