UV Light iPhone Screen Test: Detect Fake Screens in 10 Seconds

A customer once bought an iPhone 14 from Gumtree. "It's in perfect condition," they said. "The seller even showed me the screen working perfectly." But when I shined a UV light on it for three seconds, the truth came out: cheap aftermarket screen, installed poorly, already showing early signs of touch issues.

Here's what most buyers don't know: you can't tell if an iPhone screen is genuine just by looking at it. Modern aftermarket screens look nearly identical to Apple's originals—same brightness, same colors, even the same bezels. But they can have serious problems that only show up weeks or months after purchase.

After four years of inspecting refurbished iPhones across Australia and testing hundreds of screens, I'm going to show you the same method Apple-certified technicians use to detect fake screens: the UV light test. It takes 10 seconds, costs less than $20, and can save you from a bad purchase.

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Why Aftermarket iPhone Screens Are a Problem

Not all screen replacements are bad. Apple-authorized repairs using genuine parts? Those are fine. But the vast majority of screen replacements in Australia's second-hand market use cheap third-party screens from suppliers who prioritize cost over quality.

Common problems with aftermarket iPhone 14 screens:

• Touch sensitivity issues: Ghost touches, dead zones, delayed response
• Color accuracy problems: Washed-out colors, incorrect white balance
• True Tone failure: Can't adjust color temperature properly
• Shorter lifespan: Screen starts failing after 6-12 months
• Poor build quality: Gaps around edges, loose connections
• No Face ID integration: Face ID may be disabled or unreliable

I've seen phones where the screen looked perfect in a seller's photo, but in real use, the touch response was terrible, colors were off, and True Tone didn't work. By then, the buyer was stuck with a $600 phone that felt like a $200 knockoff.

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The UV Light Test: How to Check iPhone Screen Authenticity

UV light testing is the gold standard for detecting aftermarket iPhone screens. Apple-certified technicians use it, professional refurbishers use it, and now you can use it too.

The Science Behind UV Screen Testing

Genuine Apple screens use specific adhesives and coatings that do not fluoresce (glow) under 365nm UV light. Most aftermarket screens use different materials that do fluoresce—they light up bright blue, green, or purple under UV.

It's not 100% foolproof (some high-end aftermarket screens now avoid fluorescent materials), but it catches 95% of cheap replacements instantly.

What You Need for UV Light Testing

A 365nm UV flashlight (about $15-25)

Step-by-Step: How to Perform the UV Light Screen Test

1. Darken the room or test in low light (bright sunlight will overwhelm the UV effect)
2. Turn off the iPhone screen (black screen shows fluorescence better)
3. Shine the UV light along the screen edges and bezel at a 45-degree angle
4. Look for bright blue, green, or purple glow around the edges or across the entire screen

The test takes literally 10 seconds. If the screen glows under UV, it's aftermarket. If it stays dark (maybe a very faint, even glow), it's likely genuine.

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What You'll See: Genuine vs Aftermarket Screens Under UV

Genuine Apple Screen Under UV Light

What a genuine iPhone screen looks like under UV:

• Screen remains mostly dark
• Maybe a very subtle, uniform glow (barely visible)
• No bright spots, no uneven fluorescence
• Edges stay dark—no bright blue or green lines

Aftermarket Screen Under UV Light

What an aftermarket iPhone screen looks like under UV:

• Bright blue, green, or purple glow around screen edges
• Uneven fluorescence—some areas brighter than others
• Adhesive lines clearly visible in bright blue
• Sometimes the entire screen surface glows

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Other Ways to Detect Aftermarket iPhone Screens

The UV test is the most reliable, but here are some backup methods for checking iPhone screen authenticity:

Method 1: Check iOS Settings for Screen Warnings

Go to Settings → General → About. If the screen was replaced with a non-genuine part, iOS 15+ will show a warning: "Unable to verify this iPhone has a genuine Apple display." This message appears even if the phone works fine—it's Apple's way of flagging aftermarket parts.

Note: This only works if the replacement was recent and the phone is on iOS 15 or later. Older iOS versions don't show this warning.

Method 2: Inspect the Physical Screen Fit

Look closely at the screen edges for signs of poor installation:

• Are there gaps between the screen and the frame?
• Is the screen sitting unevenly?
• Can you see dust or debris trapped under the edges?

Genuine Apple screens fit perfectly flush. Poor-quality aftermarket screens often have visible gaps or misalignment.

Method 3: Test True Tone Functionality

Go to Settings → Display & Brightness → True Tone

If True Tone is grayed out or doesn't work, it's a strong indicator of an aftermarket screen. Many third-party screens can't properly replicate True Tone functionality because they lack the necessary sensors.

Method 4: Ask the Seller About Screen Replacement History

Simple but effective: "Has the screen ever been replaced?"

Honest sellers will tell you. Sketchy sellers will dodge the question ("I don't know," "I'm not sure," "It works fine"). If they can't give you a straight answer, assume the worst and bring a UV light to test it yourself.

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Should You Buy an iPhone With an Aftermarket Screen?

Not necessarily a dealbreaker—but you need to adjust your expectations and price accordingly.

When an Aftermarket Screen is Acceptable:

• The seller is upfront about it and discloses the replacement
• The price reflects the lower quality (at least $100-150 AUD discount)
• The screen works perfectly—no touch issues, no color problems
• You plan to replace it yourself eventually

When to Walk Away From a Screen Replacement:

• The seller claimed the screen was original (they lied)
• The price is the same as phones with genuine screens
• The screen already shows touch issues or color problems
• True Tone or Face ID doesn't work

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How Oloop Tests Every iPhone Screen for Authenticity

At Oloop, the UV light test is part of our standard TrueCheck™ 52+4 inspection protocol. Every single iPhone 14 that comes through gets tested under UV light—no exceptions.

What we do if we find an aftermarket screen:

1. Document it clearly in the TrueReport™
2. Test functionality thoroughly (touch response, True Tone, Face ID)
3. Grade the device accordingly (never marked as "Excellent" with aftermarket parts)
4. Price it fairly to reflect the replacement

We never hide component replacements. If a screen isn't genuine, you'll know before you buy—not after. That's the difference between professional inspection and crossing your fingers on Gumtree.

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The Bottom Line: 10 Seconds Can Save You $600

You don't need to be a phone repair expert to spot a fake iPhone screen. You just need a $20 UV flashlight and 10 seconds of your time. It's the fastest, most reliable way to verify what you're buying—whether you're meeting a private seller or buying a refurbished phone online.

The UV test isn't about being paranoid—it's about being informed. If the screen is aftermarket, fine. Just make sure you know that before you pay, and make sure the price reflects it.

And if you'd rather skip the detective work entirely? That's why every Oloop phone comes with a TrueReport™ that documents exactly what we found—including screen authenticity, tested under UV light, verified with professional tools.

Written by Jason, Founder of Oloop | Inspecting iPhones in Perth, WA | UV light screen testing since 2021 serving Australia | Updated: January 2026