Pre-meet proof

Evidence to request before you spend time travelling.

01Request rear label and on-screen informationAsk for the full model, manufacture date and an on-screen information page showing current resolution and refresh rate.
02Request solid-colour photos in a dim roomWhite, grey and black screens can reveal dead pixels, backlight bleed, burn-in and vertical bands hidden by colourful wallpaper.
03Arrange a native-resolution input testBring a known laptop or source plus certified HDMI or DisplayPort cable capable of the advertised resolution and refresh rate.

Physical inspection

What to inspect under bright light before powering on.

01Inspect panel surface and bezel seamsWith power off, use angled light to find scratches, pressure damage, coating marks and gaps from an impact or previous opening.
02Check stand, VESA points and adjustmentThe base should not rock; height, tilt and swivel should hold position. Inspect stripped VESA threads and cracks around the mount.
03Inspect inputs, power socket and controlsLook for bent connector shells, a loose power jack, missing joystick cap and ports pushed into the case.

Function test

A short, repeatable test of the device's expensive functions.

01Cycle solid colours and grayscaleInspect red, green, blue, white, grey and black at normal viewing distance and close up. Record pixel defects and persistent image retention.
02Verify native resolution and top refresh rateSelect the advertised mode in the source OS, then confirm the monitor's own information page agrees without intermittent blanking.
03Test every input and key featureSwitch through HDMI, DisplayPort and USB-C where fitted. Test USB hub, audio, KVM and adaptive-sync only if they affect your purchase.

Account & lock check

Confirm the next owner can activate and use the device normally.

01Factory-reset the on-screen menuClear custom colour, overclock, crosshair, power and input settings so faults are not masked by the seller's profile.
02Check smart-monitor and signage ownershipFor networked or smart displays, remove accounts and reject unexpected enterprise signage management or administrator PINs.
03Match serial and warranty identityCompare the rear serial with the on-screen menu and receipt where available. Confirm any remaining coverage through the maker.

Price proof

Comparable facts to record before negotiating or paying.

01Compare exact panel size and specificationMatch resolution, refresh rate, panel technology, curvature, ports and model suffix in completed sales.
02Record every pixel and uniformity defectDo not price a bright pixel, OLED burn-in or large pressure mark as generic cosmetic wear; panel replacement is often uneconomical.
03Confirm stand and power supply valueAn original stand, correct external power brick, USB-C cable or calibration accessory may be costly to replace. Generic video cables add little.

STOP

Walk-away signals

Pause the transaction when one of these cannot be resolved with direct evidence.

The monitor cannot hold its advertised native mode on a known source and cable.
Bright pixels, burn-in or pressure damage are visible in normal use.
The panel flickers, blanks or changes colour as the connector moves slightly.
The model or serial differs between rear label, menu and listing.

Safe-use boundary

Evidence helps. It does not certify the device.

DeviceProof is a general private-sale inspection aid, not an appraisal, authenticity certificate, electrical-repair guide or guarantee. Meet in a public place, keep personal passwords private, use only known-safe cables and accessories, and never bypass an owner, activation or organisation lock. Do not open mains-powered equipment or damaged batteries. Stop immediately for swelling, smoke, burning smell, exposed conductors, abnormal heat or threatening behaviour.