Galaxy S8 Plus Power Button Not Working: Fixes

If your Galaxy S8 Plus power button is unresponsive, you’re not alone—this is a common issue that can stem from software glitches, a dirty button, or hardware failure. This guide walks you through every practical fix, from simple restarts to cleaning and safe DIY repairs, so you can get your phone working again without unnecessary trips to a repair shop.

What You’ll Need

• Soft, lint-free cloth (microfiber works best)
• Isopropyl alcohol (70% or higher) or electronic contact cleaner
• Toothpick or plastic spudger (for cleaning around the button)
• SIM ejector tool or a paperclip
• Small Phillips screwdriver (for opening the phone, if you choose the hardware route)
• Replacement power button flex cable (if replacement is needed)

Step-by-Step

1. Force restart the phone. Press and hold the Volume Down and Power buttons simultaneously for 10-15 seconds. This often clears minor software freezes that make the button seem dead. If the screen turns off and the phone reboots, the button is likely working but the system was stuck.
2. Check if the button is physically stuck. Look closely at the power button. If it appears sunken or doesn’t pop back out when pressed, it may be jammed. Gently tap the button with a fingernail or the flat end of a toothpick to see if it springs back.
3. Clean the button. Dirt and grime can accumulate around the button, preventing it from making contact. Dampen a cloth with isopropyl alcohol (don’t soak it) and wipe around the button. Then, use a dry toothpick to gently scrape out any debris from the crevices. Let it dry for a few minutes before testing.
4. Use the on-screen power menu as a workaround. If the button still doesn’t work, you can still turn off/restart your phone by going to Settings > General Management > Reset > Factory Data Reset (but this wipes data—only use if you plan to reset). For a simple restart, you can also hold the Volume Down and Power button for a few seconds (this is the same as step 1). Alternatively, use the Side Key settings to assign a different action to the button (see Tips below).
5. Boot into Safe Mode. If the button works intermittently, try booting into Safe Mode to rule out third-party apps. Press and hold the Power button until the Samsung logo appears, then release and immediately press and hold the Volume Down button. Keep holding until the home screen appears with “Safe Mode” in the bottom-left corner. If the power button works fine in Safe Mode, a downloaded app is likely interfering—uninstall recently installed apps.
6. Check for software updates. Go to Settings > Software Update > Download and Install. Samsung regularly releases patches that fix bugs related to hardware buttons. Install any available updates and restart your phone.
7. Back up your data. Before attempting any hardware fix, back up your photos, contacts, and files to Samsung Cloud or Google Drive. This protects you in case something goes wrong during the repair.
8. Open the phone and inspect the button flex cable. If you’re comfortable with DIY repairs, power off the phone, remove the SIM tray, and use a heat gun or hair dryer to soften the adhesive around the back glass. Carefully pry off the back cover (using a suction cup and plastic picks), then remove the screws holding the motherboard bracket. Disconnect the battery and locate the power button flex cable (a small ribbon cable on the side of the phone). Check if it’s loose or damaged—reseat it if loose. If it’s torn, you’ll need to replace it.
9. Replace the power button flex cable. If the cable is damaged, order a replacement specific to the Galaxy S8 Plus (part number GH96-11223A or equivalent). Use a spudger to disconnect the old cable and attach the new one. Reassemble the phone carefully, ensuring all connectors are secure.
10. Take it to a professional. If the button still doesn’t work after cleaning and reseating, or if you’re not comfortable opening the phone, take it to a certified Samsung repair center or a reputable phone repair shop. They have the tools and expertise to diagnose and fix the issue safely.

Common Mistakes

• Using too much liquid when cleaning. Excess alcohol can seep into the phone and damage internal components. Always dampen the cloth, not soak it, and avoid spraying directly on the button.
• Prying with metal tools. Using a metal screwdriver to open the phone or clean the button can scratch the frame or short-circuit the board. Use plastic tools or a wooden toothpick.
• Forgetting to disconnect the battery. If you open the phone, always disconnect the battery before touching any connectors. Working on a live board can cause shorts and permanent damage.
• Assuming the button is broken when it’s just a software glitch. Many users skip the force restart and go straight to hardware repair, which is unnecessary and risky. Always try software fixes first.

Tips

• Enable “Double press” or “Press and hold” actions. Go to Settings > Advanced Features > Side Key. You can set the button to open the camera or Google Assistant, which might help you use the button even if it’s partially stuck.
• Use the “Accessibility” menu. If the button is completely dead, you can still turn off the screen by using the Assistive Menu (a floating icon). Enable it in Settings > Accessibility > Interaction and Dexterity > Assistant Menu.
• Keep the button clean regularly. Wipe the button area with a dry cloth weekly to prevent grime buildup.
• Use a case with a built-in button cover. Some cases provide a raised button that makes it easier to press and protects the button from dust.

Troubleshooting

If the button works after a force restart but fails again later: This suggests a recurring software issue. Check for updates, then boot into Safe Mode and monitor if the problem persists. If it only happens with certain apps, uninstall them.

If the button is physically stuck and cleaning doesn’t help: The button mechanism may be bent or the rubber pad underneath may be worn. You’ll need to open the phone and replace the button assembly (the flex cable includes the button).

If the phone doesn’t respond to any button combinations: The phone might be completely frozen or the battery might be dead. Plug it into a charger and wait a few minutes, then try the force restart again. If nothing happens, the issue could be more serious—consider professional diagnosis.

If you opened the phone and it won’t turn on: Double-check all ribbon cables and connectors are firmly seated. Make sure the battery is reconnected. If the screen stays black, you may have damaged a component—take it to a repair shop immediately.

Frequently Asked Questions

Can I still turn on my Galaxy S8 Plus if the power button is broken?

Yes. If the phone is off, plug it into a charger—it will auto-power on when the battery gets enough juice. If it’s on, you can use the Assistive Menu to lock the screen or restart via the notification panel (if you have a custom launcher that adds a restart button).

How much does it cost to replace the power button on an S8 Plus?

Costs vary by location and repair shop, but a typical power button flex cable replacement runs between $30 and $60 for parts and labor. DIY parts cost around $10-15.

Is the power button issue covered under warranty?

If your phone is still under Samsung’s standard 1-year warranty and the issue isn’t due to physical damage, it should be covered. Contact Samsung support or visit an authorized service center.

Can I use the Bixby button as a power button replacement?

Yes, the Bixby button (located below the volume keys) can be remapped to act as a power button. Use an app like Bixby Button Remapper (requires a one-time setup) or go to Settings > Advanced Features > Bixby Key to choose a double-press action.

Why does my power button work sometimes but not always?

This is usually caused by a loose connection or dirt. The button may make contact intermittently. Try cleaning it first, and if that doesn’t help, the flex cable may be partially detached—reseating it often fixes the issue.

Will a factory reset fix a broken power button?

Only if the problem is caused by a software bug. A factory reset will not fix a hardware issue. Try the reset only after you’ve exhausted software troubleshooting and before opening the phone, as it’s a good last software step.

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