In 2026, our smartphones rarely last more than 3 years without trouble. Update cycles that bloat operating systems, lithium batteries that degrade, miniaturised components exposed to heat and knocks, all of that accelerates wear. And yet, many common faults have simple fixes, sometimes without even seeing a technician.
This guide walks through the 10 most frequent problems I see at the workshop, with for each: the likely cause, what you can try yourself, and when it's better to hand the device to a professional.
Before any tinkering, back up your data (iCloud, Google Photos, local backup). A broken device is still a device, data, on the other hand, can be lost for good.
The 10 most common problems
1. The battery drains too fast
Likely cause: Lithium batteries naturally lose capacity after 500 charge cycles. In 2026, background apps, continuous 5G and high-refresh-rate screens (120 Hz) consume more than ever.
DIY fix: Check the battery health (iOS: Settings > Battery > Battery Health; Android: setting varies by manufacturer or app such as AccuBattery). Turn off 5G if you don't need it, reduce brightness and limit screen refresh to 60 Hz.
When to see a technician: If capacity is below 80%, battery replacement is the move. It's a routine job, done in 30 to 45 minutes at the workshop.
2. The screen no longer responds to touch
Likely cause: A screen that stops responding can come from a temporary software glitch, a poor-quality screen protector that interferes with the touchscreen, or a screen connector that's worked loose (often after a drop).
DIY fix: Restart the device. Remove the screen protector and test without it. On Android, clear the system cache (recovery mode > "Wipe cache partition").
When to see a technician: If the problem persists after a restart, or if certain areas of the screen are permanently unresponsive, there's probably a hardware fault, loose connector or touch panel to replace.
3. The smartphone gets abnormally hot
Likely cause: Heat during a call or a game is normal. On the other hand, if the phone gets hot while idle or during simple browsing, it's a sign of a background app, malware, or a swollen battery.
DIY fix: Close all apps, check which apps are draining the battery in the background, update the OS. If the back of the phone is bulging, stop charging the device : that's a sign of a swollen battery, potentially dangerous.
When to see a technician: A swollen battery is an emergency. Bring the device in without recharging it. Immediate replacement is required.
A swollen battery can rupture and cause a fire. Never press on the back of a bulging device and avoid charging it.
4. Storage is full when you've supposedly "got nothing"
Likely cause: 4K photos and videos take up far more space than people think. Apps also accumulate bulky caches. On iPhone, iCloud messages and local backups quietly swell the storage.
DIY fix: Clear app caches one by one (Settings > General > iPhone Storage, or Settings > Apps on Android). Enable cloud sync for photos and remove duplicates. Delete conversations with large attachments.
When to see a technician: A smartphone's storage isn't expandable on iPhone. On some Android devices, a microSD card can be added. If you regularly run out, advice on managing or migrating your data can save you permanent frustration.
5. The Wi-Fi connection is unstable or keeps dropping
Likely cause: A software glitch after an update, corrupted network settings or a conflict with other saved networks. Less often, a faulty Wi-Fi antenna.
DIY fix: Forget the network and reconnect. Reset network settings (without losing your data). Check whether the problem is specific to one network or to all Wi-Fi networks.
When to see a technician: If Wi-Fi doesn't work on any network and Bluetooth is also affected, it may be an antenna problem, often linked to a drop or a poorly done previous repair.
6. The camera produces blurry photos
Likely cause: In 2026, most blur doesn't come from a software focus issue, it comes from a scratched or dirty lens, or an optical image stabilisation (OIS) module damaged after a drop.
DIY fix: Gently clean the lens with a dry microfibre cloth. Test by turning off Portrait mode or digital zoom. Restart the camera app.
When to see a technician: If blur persists at all distances and the lens is clean, the camera module is probably damaged. Replacement is possible on most recent models.
7. The sound crackles or cuts out
Likely cause: Dust or a foreign body blocking the speaker grille is the most common cause, and the most overlooked. A damaged headphone jack or USB-C port can also cut sound when accessories are used.
DIY fix: Clean the speaker grille with a dry, soft brush (never water, never direct compressed air). Check that silent mode isn't enabled. Test with a Bluetooth headset to isolate the problem.
When to see a technician: If the speaker crackles or produces no sound after cleaning, it's probably oxidised or damaged. Replacement is a routine workshop job.
8. An update is stuck or fails
Likely cause: Not enough storage space to download the update, unstable Wi-Fi during the download, or partially corrupted firmware.
DIY fix: Free up at least 3 to 5 GB of space before retrying. Run the update only on stable Wi-Fi and plugged into the mains. If the device is stuck on the update screen, a forced restart (volume down + Power button held) often fixes it.
When to see a technician: If the device is stuck in a boot loop after a failed update, a restore via iTunes (iPhone) or a manufacturer tool (Android) is needed. Be aware: some restores wipe data without a backup.
9. Apps crash or close on their own
Likely cause: An app poorly optimised for the latest OS version, a lack of available RAM, or corrupted app data.
DIY fix: Update all apps from the App Store or Play Store. Uninstall and reinstall the problem app. Restart the phone to free up RAM. On Android, clear the cache of the app concerned.
When to see a technician: If all apps crash randomly after an update, a factory reset may be required, to be done after a full backup. If the problem persists after a reset, it could be a hardware fault (faulty RAM).
10. The phone is generally slow
Likely cause: In 2026, mobile operating systems are increasingly heavy. A smartphone that's 3–4 years old with 3–4 GB of RAM can quickly struggle. Full storage also drastically slows performance (the OS uses storage as virtual memory).
DIY fix: Free up storage (keep at least 10–15% free). Disable animations in developer options (Android). Reduce the number of installed apps and active widgets. A factory reset often gives a second life to an ageing device.
When to see a technician: If the smartphone stays slow after all these steps, the hardware is hitting its limits. A technician can help you assess whether it's better to optimise, replace the battery (which can also affect performance), or change device.
Quick diagnosis
- 1Start with a full restart, you'd be surprised how many problems that fixes. Hold the Power button and pick 'Restart' (not 'Power off then on').
- 2Check battery health, iOS: Settings > Battery > Battery Health. Below 80% capacity, the battery is the likely cause of many issues (slowness, sudden shutdowns, overheating).
- 3Free up storage, if you have less than 10% free space, start there. Clear caches, remove unused apps, move photos to the cloud.
- 4Update everything, OS and apps. Many bugs are fixed in updates. Check in Settings > General > Software Update (iPhone) or Settings > System > Update (Android).
- 5If the problem persists on one specific point (screen, sound, camera), see a technician for a targeted diagnosis, often free and with no commitment.
Common workshop pricing
What not to do
- Don't put a wet smartphone in rice, it doesn't dry the inside, and it can push particles into the connectors. Use silica gel sachets, or better, take it to a technician quickly.
- Don't charge a swollen battery, a bulging back is a warning sign. Make the device safe and consult immediately.
- Don't use a poor-quality, uncertified charger, surges silently damage the battery and charging circuits.
- Don't install a "RAM cleaner" app on Android, they themselves consume resources and provide no real benefit.
An unresolved problem? L'Atelier de Sam repairs all smartphones in Poitiers, often within 1 hour.
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In summary
| Problem | Likely cause | DIY action | Technician if… |
|---|---|---|---|
| Battery draining | Natural wear | Check health | Capacity < 80% |
| Screen unresponsive | Glitch or connector | Restart, remove protector | Persistent dead zones |
| Smartphone overheating | App, malware, swollen battery | Close apps, update | Bulging back, emergency |
| Storage full | Photos, caches, backups | Clear caches, enable cloud | Migration advice |
| Wi-Fi unstable | Network glitch, antenna | Forget/reconnect network | All Wi-Fi affected |
| Camera blurry | Dirty lens, damaged OIS | Clean the lens | Blur persists after cleaning |
| Sound crackling | Clogged speaker | Clean the grille | Cut or crackling sound |
| Update stuck | Storage, Wi-Fi, firmware | Free up space, retry | Boot loop |
| Apps crashing | OS, RAM, corruption | Update, reinstall | All random crashes |
| Slow phone | Full storage, insufficient RAM | Free space, factory reset | Slow after all steps |
The good news: most of these problems can be sorted without changing your smartphone. An honest diagnosis at the workshop tells you exactly what's worth repairing, and what isn't.
Frequently asked questions