Common iPhone Faults by Model: Repair & Buy Guide (2026)

Some iPhone faults show up again and again on specific models. If you repair phones, buy them second-hand, or want to know what usually goes wrong before you sell, model-specific patterns matter. From iPhone 12 display problems to iPhone 13 touch issues and iPhone 14 camera faults, this guide covers the most common reported iPhone faults by model and why they matter. Apple’s own service-programme pages confirm that at least some model-specific faults have been serious enough to warrant official repair coverage.

Here is a breakdown of the most common reported faults by model and why they matter for your next purchase or repair.

iPhone 11: The Face ID Failure

One of the most frequent headaches for iPhone 11 owners is Face ID failure. Unlike a cracked screen, this is rarely a simple part swap.

• The Problem: Users often see the dreaded “Face ID is not available” message.
• The Cause: Because the Face ID system is tightly integrated with the motherboard, it is incredibly sensitive. Moisture ingress, minor drops, or even botched previous repairs can permanently disable the sensors.
• The Impact: Since Face ID components are cryptographically “paired” to the device, fixing this requires microsoldering or official Apple intervention, making it a significant pain point for the used-phone market.

iPhone 12 & 12 Pro: No Sound and the “Green Line”

The iPhone 12 range offers two distinct angles for repair-focused content: one official and one community-driven.

• No-Sound Issue (Official): Apple launched a service program for devices manufactured between October 2020 and April 2021. A component failure on the receiver module causes a total loss of sound during calls.
• The Green Line: While not an official recall, there are widespread reports of vertical green lines appearing on the OLED displays.
• Buyer Tip: If you’re buying an iPhone 12, always check the audio during a live call and inspect the screen on a pure black background to spot early signs of display failure.

iPhone 13: The “Ghost Touch” Mystery

“Ghost touch”—where the phone performs actions without you touching it—is a recurring theme for the iPhone 13.

• Symptom-Led Search: Owners often report intermittent touch or erratic behavior.
• The Nuance: This isn’t always a factory defect. Apple’s guidance notes that non-genuine displays often cause Multi-Touch issues.
• The Verdict: If an iPhone 13 is acting up, it’s often a sign of a poor-quality previous repair. This makes it a great topic for repair shops to educate customers on the importance of high-quality panels.

iPhone 14 Plus: Rear Camera No-Preview

This is currently one of the strongest “fault” topics because it is backed by an Official Apple Service Program.

• The Issue: A small percentage of iPhone 14 Plus units (manufactured between April 2023 and April 2024) show a black screen instead of a preview when using the rear camera.
• The Solution: Apple provides a serial number checker to see if a device is eligible for a free repair. For resellers, checking this serial number before buying is a mandatory step to protect your margins.

iPhone 14 Pro / Pro Max: Back Glass Fragility

For the flagship 14 Pro series, the issue isn’t a software bug or a failing chip—it’s the complexity of the build.

• Repair Difficulty: While the standard iPhone 14 saw a redesigned internal structure for easier glass replacement, the 14 Pro and Pro Max remained more traditional (and difficult) to open.
• The Risk: Shattered back glass on a Pro model isn’t just cosmetic; it compromises waterproofing and is significantly more expensive to fix than users expect. For second-hand buyers, a “small crack” in the back can hide a very expensive repair bill.

Why These Patterns Matter

Understanding these faults allows you to price in the risk. A phone with a known weak point can still be a fantastic deal, provided the price reflects the potential repair cost.

The most successful players in the mobile industry don’t search for “phone bugs”; they look for symptoms. By matching common searches—like “iPhone 12 green line” or “iPhone 11 Face ID unavailable”—with these known patterns, you can make more informed decisions as a consumer or a technician.

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