Samsung Galaxy S20 Will Not Turn On
This guide helps troubleshoot a Samsung Galaxy S20 that won't turn on or respond to power button inputs.
Step 1 | Battery Discharged
Phone requires battery power to operate.
- Low battery alert may not appear on screen when power button pressed, indicating extremely low charge level.
- Try charging phone for at least 10 minutes before attempting to turn it back on.
Verify functionality of cable, charging block, and outlet to rule out simple discharge as the cause. Plug in another USB-C device if necessary.
Step 2 | Firmware Fault
Perform a force reset if the problem appears unrelated to external factors.
- Press and hold power & volume down buttons for 10-30 seconds on Galaxy S20.
- Release when Samsung logo appears; phone should start normally.
- If logo doesn't appear, try plugging in for 10 minutes, then retry while connected to power.
A successful reset may indicate a software issue, but hardware malfunction possible if this doesn't work.
Step 3 | Bad Battery
Lithium Ion batteries like the one in your Galaxy S20 have limited charge cycles (400-500) before capacity degrades to 80%.
- Most users notice battery degradation at 1-1.5 years, with reduced charge hold and longer charging times.
- At 50-60% capacity, the battery may fail to hold a useful charge and struggle providing power.
If you've used your phone for 2-3+ years (1,000+ cycles), it may have trouble starting up, even when fully charged.
Checking Battery Status:
- Open the Samsung Members app and select Get Help.
- Select Interactive Checks and then Battery from the list of components to check.
Avoid keeping your phone's battery at extreme charge levels (fully charged or fully discharged) for long periods, as this can degrade battery life significantly.
Replacing a Degraded Battery:
- Use the Samsung Galaxy S20 Battery Replacement guide to replace the battery with one of the following options:
- Samsung Galaxy S20 FE 5G
- Samsung Galaxy S20 5G
- Samsung Galaxy S20+ 5G
- Samsung Galaxy S20 Ultra 5G
Step 4 | Screwed-Up Screen
A faulty screen may cause the phone to appear as if it won't turn on.
- Inspect for visible damage if phone has recently been dropped.
Test phone by connecting to external display, if available. If output is received, display is likely damaged but internals are functioning.
Use a USB ammeter to confirm charging port functionality and rule out internal issues.
- Replace screen with a new one using the correct guide for your Samsung Galaxy S20 model:
- Samsung Galaxy S20 Screen Replacement
- Samsung Galaxy S20 Plus Screen Replacement
- Samsung Galaxy S20 Ultra Screen Replacement
- Samsung Galaxy S20 FE Screen Replacement
Step 5 | Motherboard Malfunction
If other solutions fail, a faulty main circuit board (motherboard) might be the issue.
- The motherboard controls most of the phone's functions, including input processing from screen and buttons.
- Other components on the motherboard include Qualcomm Snapdragon 865 SoC, RAM module, flash storage, and 5G modem.
The motherboard usually fails due to significant impact, water exposure, extreme temperatures, or changed BIOS settings.
If you suspect a damaged motherboard, replace it to regain functionality.