Phone won't turn on? What to try first

The short answer

A phone that won't turn on usually has a drained or failed battery, a failed screen (the phone is on but dark), a software crash, or a fault on the logic board. Charge it for 30 minutes with a charger you know works, then try a forced restart, before assuming it is dead.

Symptoms

• Completely dead: no light, sound or vibration
• Black screen, but it still rings or vibrates
• Stuck on the Apple or Samsung logo, or restarting in a loop
• Turns on, then shuts off again
• Stopped working after a drop or after getting wet

Safe checks to try first

1. Charge for at least 30 minutes with a known-good cable and adapter.
2. Force a restart. On recent iPhones: press volume up, then volume down, then hold the side button until the logo appears. On most Samsung phones: hold power and volume down together for 10 seconds or more.
3. Check whether it is on but dark: call it, flip the ring switch, or plug it into a computer and see whether it is detected. If so, the screen is the likely fault.
4. If it got wet, do not charge it and do not keep trying to turn it on.
5. If the data matters and isn't backed up, do not run a restore. A restore erases the phone.

How we diagnose it

We power the phone from a bench supply and read how much current it draws, which shows whether the fault is the battery, the screen or the board. We test with a known-good screen and battery, then inspect the board under a microscope if needed.

Repair options

• Battery replacement
• Screen replacement, when the phone is on but the display is dead
• Software repair, which may erase data; we tell you first
• Board-level repair by micro soldering, usually 1 to 5 days
• Data recovery, when the phone itself isn't worth repairing but what's on it is

When repair may not be possible

A cracked board, or damage to the main processor or storage chip, often can't be repaired, and in those cases the data may not be recoverable either. We tell you plainly if that is what we find, and diagnosis is no fix, no fee.