iPhone Troubleshooting Guide: Fix Every Common Problem (2026)

Your iPhone has stopped doing what it's supposed to do. Maybe the screen has gone haywire, the battery is draining before lunch, or it simply won't turn on. Before you panic — and definitely before you start searching for a replacement — take a breath. Most iPhone problems have straightforward solutions, and this guide will walk you through every common issue we see at celltech.

We've repaired tens of thousands of iPhones at our Solihull workshop over the years, and the vast majority of faults fall into a handful of categories. This pillar guide organises every common iPhone problem into clear sections, explains what's likely causing it, and links you to our detailed troubleshooting guides for each specific issue. Think of it as your complete reference — bookmark it, and you'll never need to trawl through dozens of search results again.

Need it fixed now? Skip the troubleshooting and book a free diagnostic through celltech's UK-wide fast mail-in repair service. celltech handles UK-wide mail-in repairs.

Quick Diagnosis: Find Your Problem

Use this table to jump straight to the section that matches your symptom. Each links to a dedicated in-depth guide.

Now let's break these down properly.

Screen Issues

Screen problems are the most visible — literally. Whether your display is flickering, refusing to respond to touch, or Face ID has suddenly stopped recognising you, screen faults can make your iPhone feel completely unusable. The good news is that most screen issues are repairable, and many don't even require a full screen replacement.

Touch Screen Not Responding

An unresponsive touch screen is one of the most frustrating iPhone problems. You can see everything on screen, but your phone completely ignores your input. This can be caused by a software crash (fixable with a force restart), a damaged digitiser layer, or a loose display connector inside the phone.

Before assuming the worst, try a force restart: press and quickly release Volume Up, then Volume Down, then hold the Side button until the Apple logo appears. If the screen still won't respond to touch after restarting, the digitiser or display connector likely needs attention.

Our full guide covers every possible cause and walks you through each fix: iPhone touch screen not working — complete troubleshooting guide.

Screen Flickering or Flashing

Flickering can range from a subtle shimmer to violent flashing that makes the phone unusable. On older models like the iPhone X and 11 series, this is often caused by a failing display IC chip — a component on the logic board that controls the display. On newer models, it's more commonly a loose display connector or damage to the OLED panel itself.

Software-related flickering can sometimes be resolved by adjusting display settings or performing a factory reset, but hardware flickering requires professional diagnosis. Don't ignore it — intermittent flickering almost always gets worse over time.

Read the full breakdown: iPhone screen flickering — causes and fixes.

Face ID Not Working

Face ID relies on a sophisticated array of sensors housed in the notch (or Dynamic Island on newer models). If Face ID stops working after a drop, it's likely that the TrueDepth camera or flood illuminator has been damaged. If it stops working after a screen repair done elsewhere, the repair shop may not have transferred the Face ID components correctly — this is surprisingly common with cheap repairs.

Software fixes include resetting Face ID in Settings > Face ID & Passcode and re-enrolling your face. If that doesn't work, the sensor hardware needs inspection.

Full guide: iPhone Face ID not working — troubleshooting and repair. For broader screen repair information, see our complete iPhone screen repair guide.

Power & Battery Problems

Battery and power issues account for a huge proportion of the repairs we handle at celltech. Lithium-ion batteries are consumable components — they degrade with every charge cycle, and most iPhones will need a battery replacement after 2-3 years of regular use. But not every power problem is the battery's fault.

iPhone Won't Turn On

A completely dead iPhone is alarming, but it doesn't necessarily mean the worst. The most common cause is simply a fully depleted battery — plug it in and wait 15-30 minutes before trying to turn it on. If you see a red battery icon appear on screen, the battery is charging and you just need to be patient.

If nothing happens after 30 minutes of charging, try a different cable and charger (genuinely — faulty cables are incredibly common). If it still won't respond, the issue could be a completely failed battery, a damaged charging circuit, or a logic board fault.

Our detailed guide walks through every diagnostic step: iPhone won't turn on — what to do.

Battery Draining Fast

If your iPhone used to last all day and now barely makes it to the afternoon, you're dealing with either a degraded battery or excessive background activity. Check Settings > Battery > Battery Health & Charging. If your maximum capacity is below 80%, the battery is the culprit and replacement will likely solve the problem.

If battery health is above 80%, the drain is almost certainly software-related: rogue apps running in the background, excessive location services, push email fetching too frequently, or a buggy iOS update. Our guide covers every possible cause: iPhone battery draining fast — fixes that actually work.

When you do need a new battery, our complete battery replacement guide covers pricing for every model, what to expect, and why professional replacement beats DIY.

Battery Swelling

A swollen battery is the one iPhone problem that qualifies as genuinely urgent. If your screen is lifting away from the frame, there's a visible bulge on the back of your phone, or the display has a strange pressure mark, stop using the phone immediately. A swollen lithium-ion battery is a fire and chemical burn risk.

Don't charge it. Don't try to force the screen back down. Don't put it in a confined space. Bring it to a professional as soon as possible. At celltech, we treat swollen battery cases as priority repairs.

Read our safety guide: iPhone battery swelling — what it means and what to do.

Safety first: A swollen battery is the only iPhone problem where we'd say stop reading guides and get professional advice immediately. Email us on mail@celltechmobilerepairs.co.uk before posting the device.

Stuck on Apple Logo

Your iPhone starts to boot, shows the Apple logo... and stays there. This boot loop is usually caused by a failed iOS update, corrupted system files, or — less commonly — a hardware fault. It's one of those problems that looks catastrophic but is often fixable with a recovery mode restore.

The key concern for most people is data. If you have a recent iCloud or computer backup, a restore will get you back up and running quickly. If you don't have a backup, a professional repair shop can often recover data from a boot-looping iPhone using specialist tools.

Step-by-step instructions: iPhone stuck on Apple logo — how to fix it.

iPhone Overheating

All iPhones generate heat during intensive tasks — that's normal. What's not normal is a phone that gets uncomfortably hot during basic use, displays a temperature warning, or feels warm even when idle. Overheating can be caused by a failing battery, a rogue app consuming excessive processor time, charging with a faulty cable, or environmental factors (direct sunlight, cases that trap heat).

Persistent overheating damages internal components and accelerates battery degradation, so it's worth investigating promptly. Our guide explains how to identify and resolve every common cause: iPhone overheating — causes and solutions.

Charging Problems

Charging issues are the second most common category we see after screen damage. The Lightning port (or USB-C on iPhone 15 and later) takes a beating — it's exposed to pocket lint, dust, moisture, and the mechanical stress of plugging and unplugging cables hundreds of times a year.

iPhone Not Charging

Before assuming a hardware fault, clean the charging port. Seriously — a compressed air blast or a careful clean with a wooden toothpick removes the compacted lint that accumulates in every pocket-carried phone. This single step fixes the problem for roughly 30% of the "not charging" cases we see.

If cleaning doesn't help, test with a different cable and power adapter. Apple's MFi-certified cables are worth the investment — cheap uncertified cables are a common cause of charging problems and can even damage the charging IC.

When the port itself is damaged, a charging port replacement is a straightforward repair. Our full troubleshooting guide covers every scenario: iPhone not charging — complete guide.

iPhone Charging Slowly

Slow charging is often mistaken for a fault when it's actually a configuration issue. The 5W adapter that used to ship with iPhones charges at a fraction of the speed that modern iPhones support. An iPhone 15 Pro with a 20W adapter and USB-C cable can reach 50% in roughly 30 minutes — with a 5W adapter, the same charge takes over two hours.

If you're already using an appropriate adapter and the charging is still slow, the causes overlap with the "not charging" scenario: port contamination, cable degradation, or charging IC issues. Background activity during charging can also slow things down significantly — especially navigation, gaming, or video calls.

Full guide: iPhone charging slowly — why and how to fix it.

Audio Problems

Audio faults can affect calls, media playback, voice recordings, and Siri — depending on which component is affected. The iPhone has multiple speakers and microphones, and identifying which one is faulty is the first step to a fix.

Speaker Not Working

The iPhone has two speaker outputs: the earpiece (top) and the bottom-firing speaker. If one works but the other doesn't, you've already narrowed down the problem. A completely silent phone — no ringer, no media, no call audio — is more likely a software issue or a logic board fault.

Check the obvious first: is the phone on silent (the physical switch on the left side)? Is Bluetooth connected to a speaker or headphones you've forgotten about? Is the volume turned all the way down? These sound basic, but they account for a surprising number of "broken speaker" reports.

If it's genuinely a hardware fault, speaker replacement is one of the quicker iPhone repairs. Full guide: iPhone speaker not working — troubleshooting guide.

Microphone Not Working

Modern iPhones have three microphones: bottom (primary for calls), front (FaceTime and Siri), and rear (video recording and noise cancellation). If people can't hear you on calls but voice memos work fine, the bottom microphone is likely blocked or damaged. If video recordings have no audio, it's the rear microphone.

A blocked microphone hole is the most common cause. Cases with poor cutouts, screen protectors that overlap the earpiece area, and accumulated dust can all muffle or block the microphone. Try recording a voice memo and playing it back — this is the quickest way to test whether the primary microphone is working.

Detailed troubleshooting: iPhone microphone not working — diagnosis and fixes.

Camera Problems

Camera Not Working

Camera issues range from a completely black viewfinder to blurry photos, a shaking image, or the flash refusing to fire. The iPhone's camera system has become increasingly complex with each generation — the iPhone 15 Pro Max has a 48MP main sensor, ultrawide, and 5x telephoto, each with its own hardware that can fail independently.

Software fixes include force-closing the Camera app, restarting the phone, and checking for iOS updates (Apple has released patches specifically for camera bugs). If the camera lens is physically cracked, that's an obvious hardware repair. Less obviously, a camera that shakes or vibrates may have a failed optical image stabilisation (OIS) module — the tiny gyroscope that keeps your photos steady.

Our complete guide covers every camera fault and fix: iPhone camera not working — what to check and how to fix it.

Water Damage

What to Do When Your iPhone Gets Wet

Despite Apple's IP68 water resistance rating on recent models, water damage remains one of the most common iPhone repairs we handle. Water resistance degrades over time — every drop, bump, and screen repair can compromise the seals. And the rating only covers clean, still water — not bathwater with soap, seawater with salt, or pool water with chlorine.

If your iPhone has been submerged or exposed to significant moisture, the critical steps are: power it off immediately, don't charge it, don't try to dry it with heat (hairdryers are a terrible idea), and don't put it in rice (this is a myth that can actually introduce starch particles into the phone). Shake out excess water gently with the port facing down, then bring it to a professional as quickly as possible.

Time is the enemy with water damage. The longer moisture sits on the circuit board, the more corrosion develops. We've saved iPhones that were brought in within hours of submersion — and declared total losses on phones where the owner waited a week while "drying it in rice."

Our emergency guide covers exactly what to do in the first critical minutes and hours: iPhone water damage — immediate steps and recovery guide.

Water damage warranty: At celltech, water damage and board-level repairs carry a 120-day warranty. We use ultrasonic cleaning to remove corrosion at the component level — not just a "dry it out and hope" approach.

When to Fix It Yourself vs. When to Bring It In

We're a repair shop, so you might expect us to say "bring everything to us." But honestly, some iPhone problems genuinely don't need professional help. Here's how we'd categorise them:

Safe to Try Yourself

• Force restart — fixes many software glitches, boot loops, and frozen screens. No risk whatsoever.
• Cleaning the charging port — use a wooden toothpick, never metal. Fixes a surprising number of charging issues.
• Software settings — resetting Face ID, checking silent mode, toggling Bluetooth, adjusting battery settings.
• iOS updates — Apple regularly patches bugs that cause camera, audio, and battery issues.
• Recovery mode restore — if your phone is stuck on the Apple logo and you have a backup, this is safe to attempt via a computer.
• Checking accessories — swap cables, adapters, and cases before assuming a hardware fault.

Bring It to a Professional

• Swollen battery — safety risk, do not attempt to open the phone yourself.
• Water damage — needs ultrasonic board cleaning within hours, not days of rice.
• Cracked or shattered screen — requires specialist tools, adhesive, and calibration. See our screen repair guide.
• Face ID failure after a drop — TrueDepth sensor components are extremely delicate.
• No power after charging — could be battery, charging IC, or board-level fault.
• Microphone or speaker hardware failure — requires disassembly.
• Camera shake or OIS failure — internal module replacement needed.
• Screen flickering — likely display IC or connector issue, needs board-level diagnosis.
• Any repair you're not 100% confident about — the cost of a botched DIY repair is always higher than getting it done right the first time.

Free diagnostics: If you're unsure what's wrong, book a free diagnostic through our mail-in service. We'll tell you exactly what's causing the problem and give you a quote before doing any work. No obligation, no pressure. Book now.

Preventing iPhone Problems

Most iPhone faults are preventable with a few simple habits:

• Use a quality case — a decent case with raised edges around the screen and camera prevents the vast majority of drop damage.
• Apply a tempered glass screen protector — they're cheap and absorb impacts that would otherwise crack your display.
• Keep the charging port clean — a quick blast of compressed air every few months prevents the lint buildup that causes charging faults.
• Use certified cables and adapters — MFi-certified accessories won't damage your charging circuitry.
• Avoid extreme temperatures — don't leave your phone on a car dashboard in summer or outside in freezing conditions.
• Replace the battery proactively — once battery health drops below 80%, replacement prevents the cascade of issues that a degraded battery causes (shutdowns, slow performance, overheating).
• Keep iOS updated — Apple patches security vulnerabilities and bugs with each release.
• Back up regularly — this won't prevent hardware problems, but it means any repair or replacement is painless in terms of data.

Frequently Asked Questions

How do I force restart my iPhone?

Press and quickly release Volume Up, then Volume Down, then hold the Side button until the Apple logo appears. This works on iPhone 8 and later. For iPhone 7, hold Volume Down and the Side button together. For iPhone 6s and earlier, hold the Home button and the Side button together. A force restart doesn't delete any data.

My iPhone is completely dead — is my data gone?

Almost certainly not. A dead iPhone usually means a dead battery or a power delivery fault — your data is stored on the NAND flash memory, which doesn't require power to retain information. In the vast majority of cases, once the underlying fault is repaired, your data will be exactly where you left it. Even in worst-case scenarios, specialist data recovery can often retrieve information from the storage chip directly.

Should I put my water-damaged iPhone in rice?

No. This is a persistent myth. Rice does not actively draw moisture out of electronics — it's less effective than simply leaving the phone in open air. Worse, rice dust and starch particles can enter the phone through the charging port and speaker grilles, causing additional problems. If your iPhone has been exposed to water, power it off, shake out excess liquid, and bring it to a repair professional as quickly as possible. Read our water damage emergency guide for the full protocol.

How do I check my iPhone's battery health?

Go to Settings > Battery > Battery Health & Charging. The "Maximum Capacity" percentage tells you how much charge your battery can hold compared to when it was new. Apple considers a battery to be "consumed" at 80% — below this, you'll notice shorter battery life, potential shutdowns, and reduced performance. Our battery drain guide explains what each reading means and when replacement makes sense.

Why does my iPhone get hot when charging?

Mild warmth during charging is completely normal — especially with fast charging. However, if the phone gets uncomfortably hot, it could indicate a faulty cable, a degraded battery struggling to accept charge, or heavy app usage during charging. Remove the case while charging (cases trap heat) and avoid using processor-intensive apps simultaneously. If it continues, see our overheating guide.

Can celltech fix iPhones that other shops couldn't?

Often, yes. We handle board-level microsoldering repairs that most high-street shops aren't equipped for — including display IC replacement, charging IC repair, audio IC fixes, and data recovery. If you've been told a phone is "beyond repair," it's worth getting a second opinion. Our diagnostics are free, and there's no charge if we can't fix it.

Do I need an appointment?

No. Mail-in repairs are available UK-wide. For complex repairs, emailing ahead at mail@celltechmobilerepairs.co.uk helps us prepare the right parts, but it's not required. We also offer a UK-wide mail-in service — Use the posting instructions and we'll have your phone diagnosed within 24 hours of receiving it.

What warranty do celltech repairs carry?

Standard repairs (screens, batteries, cameras, speakers, buttons) carry our 27-month warranty — one of the longest in the UK. Connector repairs (charging ports, headphone jacks) carry a 9-month warranty. Board-level repairs, microsoldering, water damage treatment, and data recovery carry a 120-day warranty. Every repair is fully tested before return.

Get Your iPhone Fixed at celltech

Whether you've worked through the troubleshooting steps above and identified a hardware fault, or you'd rather skip straight to a professional diagnosis, we're here to help. Every repair starts with a free diagnostic — we'll tell you exactly what's wrong and what it will cost before we touch anything.

• Mail-in: Book online and send by Royal Mail Special Delivery using the shipping instructions sent after checkout
• Email: mail@celltechmobilerepairs.co.uk
• Mail in: UK-wide service — Use the posting instructions
• Warranty: Up to 27 months on standard repairs

Book your free diagnostic now — or browse our full range of iPhone repair services.

Related guides: iPhone battery replacement — complete pricing guide • iPhone screen repair guide • iPhone charging port repair guide