Phone Screen Test Guide
Refurbished phones are everywhere and OLED burn-in is permanent — new or used, run the 8 steps before you pay.
Why You Need This
Refurbs are everywhere
Aftermarket screens passed off as original are the oldest trick: dull colors, no high refresh, low touch sampling — the 8 steps expose them on the spot.
OLED burn-in is forever
Burn-in can’t be repaired and is rarely covered. Two minutes on grey/white screens reveals it — saving you a screen replacement later.
New phones aren’t exempt
Green-tint batches, dead pixels and touch issues do ship in first production runs — test within the 7-day window.
No app needed
Everything runs in the browser — complete every check on the spot with the phone’s own browser.
The 8-Step Inspection Flow
Test each item in order — every step links to a free online tool.
Dead Pixels
EssentialCycle solid colors to spot bright/dark pixels — pay attention to curved edges and around the camera hole.
Verdict：Even a single bright or dead pixel justifies a return.
Open ToolBurn-in
EssentialA must for used OLEDs: look for status-bar, keyboard or nav-button ghosts on white and grey screens.
Verdict：Any fixed ghost visible on white is burn-in — negotiate hard or walk away.
Open ToolTouch Test
EssentialDrag across the whole screen to draw trails and catch dropouts, phantom touches or dead zones — edges and corners first.
Verdict：Multi-touch dropouts or fixed dead zones usually mean a swapped screen or cable issue.
Open ToolColor Gamut
RecommendedVerify 100% DCI-P3 with wide-gamut patterns; aftermarket screens typically look dull with visibly shrunken gamut.
Verdict：Dull colors with no system gamut modes suggest a non-original panel.
Open ToolBrightness
RecommendedMax out brightness on a white screen, then check whether auto-brightness visibly boosts peak outdoors.
Verdict：Peak brightness far below spec (e.g. “1200 nits” looking dim) warns of a non-original panel.
Open ToolRefresh Rate (LTPO)
RecommendedMeasure real refresh rate while scrolling; LTPO panels should drop to 10Hz/1Hz when static to save power.
Verdict：No high-refresh option in settings or a measured 60Hz lock suggests a swap or missing feature.
Open ToolPWM Flicker
OptionalAt low brightness, film the screen in slow motion with another phone — rolling stripes reveal PWM frequency.
Verdict：Flicker-sensitive users should pick 2160Hz PWM or DC-like dimming models.
Open ToolGreyscale
OptionalAt low brightness, check dark greys for green/purple tinting (common on OLED) and confirm highlights stay clean.
Verdict：Severe tinting that hurts night use — try an exchange if other units don’t show it.
Open ToolKey Terms
LTPO
Variable refresh tech — drops to 1-10Hz on static content and snaps back to 120Hz when you scroll.
PWM Dimming
Brightness via rapid pixel switching. Lower frequencies fatigue eyes; 2160Hz+ is eye-friendly.
Peak Brightness
Maximum brightness on small HDR highlights — different from full-screen brightness; marketing quotes peak.
Touch Sampling
How often touch is read per second (Hz). Higher is more responsive; gaming phones reach 480Hz+.
Pentile Matrix
Shared-subpixel OLED layout; effective sharpness is slightly below RGB LCD — text edges look softer up close.
Gamut
Phones commonly advertise DCI-P3 wide gamut; aftermarket panels often cover only 70-80% of sRGB.
Colorimeter / certified cable recommendations coming soon.
Panel Technology Compared
OLED
Flagship- True black, efficient, high contrast
- Enables curved/folding
- Burn-in risk
- Low-brightness tint & PWM
LCD
Durable- No burn-in or PWM
- RGB matrix is sharper
- Low contrast
- Thicker bezels
国产平替屏
Used-market trap- Cheap to repair
- Poor accuracy & brightness
- Low touch sampling, no high refresh
- Often lacks True Tone/auto-brightness
Return vs Normal
Should Return
- Burn-in ghosts visible on white (status bar / keyboard imprint)
- Multi-touch dropouts, phantom touches or fixed dead zones
- Any bright or dead pixel, including curved edges
- Lifted adhesive, warped screen or creaking under pressure
- Non-original signs: dull colors, no high-refresh option, no auto-brightness
Normal Behavior
- Slight green/purple tint in dark greys at very low brightness (OLED trait)
- Mild green edge tint on curved displays (optical refraction)
- Low-brightness PWM flicker (sensitive users should choose 2160Hz models)
- Minor auto-brightness fluctuation under strong light
- Slightly soft text edges up close due to Pentile layout