How to Fix iPhone 15 Won't Turn On

By Rob · Editor, Tech Problem Solved

This guide is a practical, ordered fix for Won't Turn On on iPhone 15 running iOS. Start with the least destructive checks, then software repairs, and only then a backup-and-reset. Each numbered step includes a simple diagram so you can match what you see on screen. On iPhone 15, a true force restart uses volume up, volume down, then hold Side — holding only the Side button opens Siri/power off and will not clear many freezes.

Who this guide is for

• Primary device: iPhone 15
• Software family: iOS
• Brand: Apple
• Nearby models in the same brand/OS generation usually follow the same order of checks.

Editor notes before you start

• This guide is written for iPhone 15 on iOS. Sister Apple models are often similar, but menu labels can move after an update — use Settings search when a path differs.
• We keep these guides intentionally focused: fewer pages, clearer steps, and honest stop-points before unsafe hardware work.

What you will need

• 10–15 minutes without rushing
• Your device passcode / password
• A known-good wall charger and cable rated for this device
• A second wall socket to rule out a dead outlet

Before you start

• Save any open work on iPhone 15 if the device is still responsive.
• Back up photos and documents before any reset step — cloud or computer copy.
• Work through the steps in order; skip ahead only if a step clearly does not apply.

Symptoms

• No logo, backlight or vibration when you press the power button.
• A battery icon may flash briefly, then the screen goes dark again.
• The device feels completely unresponsive even when left on charge for 20+ minutes.

Common causes

• Deeply discharged battery that needs several minutes on a known-good charger
• Failed iOS update leaving the device in a recovery-like state
• Faulty Lightning/USB‑C cable or under-powered brick
• Liquid damage or a failing power button flex

Step-by-step fix

1

Force a clean power cycle

On iPhone 15, press volume up, volume down, then hold the side button until the Apple logo. Ignore the power-off slider — keep holding until the Apple logo. Wait 30 seconds, then unlock and test.

2

Prove power is reaching the device

Leave iPhone 15 on a known-good charger for at least 20 minutes. Look for any LED, logo, vibration or battery icon. Swap cable and brick before assuming a dead battery.

3

Check for a recovery / download mode situation

If iPhone 15 sits on a cable icon, connect to a computer and use Finder/iTunes recovery — update first, restore only if update fails. This erases the phone if you restore.

4

Reset the related setting (not the whole device yet)

Use the least destructive reset in Settings / Settings → General → Transfer or Reset iPhone/iPad → Reset that targets this symptom (network, keyboard dictionary, all settings) before erasing personal data.

5

Last resort: backup then reset

Back up iPhone 15 to a computer or iCloud. Then Erase All Content and Settings. Set up as new to test — restore the backup only after the fault is gone, or restore selectively.

What success looks like

iPhone 15 boots to the lock screen or home screen and stays responsive for a normal session.

Prevention tips

• Do not force-shutdown during OS updates.
• Use the manufacturer’s wattage guidance for chargers.
• Stop DIY if you smell burning, see liquid damage indicators, or the chassis is swollen.

When to get professional help

Stop and seek a reputable repairer if iPhone 15 smells of burning, the back glass is lifting (swollen battery), you see liquid damage, or there is still no charge indicator after testing two known-good chargers and cables. Do not puncture a swollen battery.

FAQs