Samsung Galaxy S21 Won’t Turn On: How To Fix It

Your Galaxy S21 has a black screen, nothing happens when you press the Side key, and you are wondering if it is dead.

Usually it is not, because a software freeze or a fully drained battery causes this far more often than a hardware failure.

The steps below follow Samsung’s own support guidance and take about 10 to 30 minutes.

Quick answer: what to try first

Samsung lists four possible causes: a temporary software freeze, a fully drained battery, a system malfunction, or a hardware problem (Samsung US support).

Step	What to do	Time
1	Look for damage and moisture	1 minute
2	Force restart: Side key plus Volume Down	7+ seconds
3	Charge with a Samsung-certified charger and cable	15 to 20 minutes
4	Try a different charger and cable	Few minutes
5	Contact Samsung for service	Varies

InspectForce restartChargeNew cableSamsung service

Step 1: check for physical or liquid damage

Look at the frame and screen for cracks and dents, especially if the phone was dropped before it went dark.

The Galaxy S21 is rated IP68, meaning dust and water resistant up to 1.5 m for 30 minutes, but that is not the same as waterproof.

Check the charging port for wetness, and if you find damage or liquid, skip ahead to the service section.

Step 2: force restart the phone

A force restart is the fix Samsung lists first for a frozen phone that will not respond.

Press and hold the Side key and Volume Down together for at least 7 seconds.
Release both when the Samsung logo appears and the phone vibrates.
Let it finish booting.

Samsung says that if the volume bar or power menu appears, the buttons were not pressed together, and that a case can get in the way.

Another Samsung page says the logo can take 10 seconds or longer, so keep holding past 7 seconds.

Step 3: charge it with a certified charger

A completely drained battery may show no charging icon at all, so keep charging even if the screen stays blank.

Samsung’s guidance is to leave it connected for about 15 to 20 minutes before trying to turn it on.

Use a Samsung-certified charger and cable.
Plug the charger into a working outlet.
Do not use worn or damaged accessories.

After the wait, try the force restart again, as described by Samsung Canada support.

Step 4: swap the charger and cable

If no charging icon or battery percentage shows after a few minutes, the problem may be the charger or cable, not the phone.

Try a spare charger and data cable, then turn the phone on.

If your phone supports wireless charging, a wireless pad is another way to test without using the port.

Why the S21 and charger confusion is common

The Galaxy S21 launched without a charger plug in the box, so many owners charge with older accessories.

Samsung said it was removing the plug and earphones from new Galaxy boxes and that its USB-C ports let older chargers keep working (Tom’s Guide report).

For this fault, though, Samsung’s support pages still say to test with a Samsung-certified charger and cable.

Part	What to check	Source
Charger plug	Certified, undamaged, in a working outlet	Samsung US and Canada
USB-C cable	Not worn or damaged; try a spare	Samsung US
Charging port	Dry, with nothing inserted into it	Samsung US
Case	Remove it before pressing both keys	Samsung US

If the charging port is wet

Do not charge a wet phone, because Samsung says plugging in while the port is wet sounds an alarm.

Disconnect the charger and gently shake the phone.
Wait; Samsung says water typically evaporates from the port within about 1 to 2 hours.
If the liquid was not fresh water, rinse the port in fresh water and dry it with a soft cloth.
Do not insert objects into the port.

Details are on Samsung’s moisture page.

Which symptom points to which fix?

Symptom	Try	Source
Black screen, no response	Force restart (Step 2)	Samsung US
Volume bar or power menu appears	Press Side and Volume Down together; remove case	Samsung US
No charging icon	Keep charging, then new cable	Samsung US
Alarm or water warning when plugged in	Unplug, dry, wait 1 to 2 hours	Samsung US
Shuts down after update or crashes	Safe mode or service	Samsung US

If it powers on but keeps crashing: Safe mode

Safe mode switches off downloaded apps so you can tell whether one of them is the cause.

Hold Volume Down and the Side key until the Power off menu appears.
Touch and hold the Power off icon until Safe mode appears, then tap it.
If the problem stops, uninstall the most recent app you installed before it began.
To exit, hold Volume Down and Side, tap Power off, wait, then press the Power button.

Samsung says that if the problem continues in Safe mode, it is likely hardware, per its boot-loop page.

Factory data reset as a last resort

Only use this once the phone stays on long enough to reach Settings, and back up first because data may not be recoverable.

Open Settings, then General management.
Tap Reset, then Factory data reset.
Tap Reset, then Delete all.
Enter your Samsung account credentials.

If the phone does turn on but keeps restarting, see our guide to Galaxy S21 rebooting or Galaxy S21 crashing.

What to avoid while troubleshooting

Charging a wet phone: Samsung says not to charge it while wet.
Poking the port: Samsung says not to put any object into the charging port.
Damaged accessories: Samsung warns against worn or damaged chargers and cables.
Resetting without a backup: Samsung says data may not be recoverable after a factory reset.

When to contact Samsung or get service

If a force restart, a certified charger and a second cable all fail, the phone needs inspection.

Use online chat or the Samsung Members app through Samsung’s Get support link.
Visit a Samsung walk-in service center or schedule a repair online.
Register the product, then use Request Service under My Page and Products on Samsung.com.

Check your warranty status first, since Samsung’s warranty page says to check device details for coverage.