Samsung Galaxy S21+ troubleshooting

Published specification

What is true of this model and changes how you fix it

• What owners run into
  At five years old the battery is tired, so complaints are about short life, sudden shutoffs and slow charging. The phone is past its update window and no longer receives new Android versions.
• How to approach a fault
  Replace the battery if shutoffs occur above 20 percent, and keep the phone off hot chargers. Back up before service.
• Finding your model and software
  Settings, About phone shows the model number and patch date. The S21+ is past its update promise, so the patch date is frozen at its last release.
• Why an old phone shuts off
  A tired battery cannot deliver peak current, so the phone shuts off at 20 or 30 percent, especially in cold weather. A new battery, which Samsung or a repair shop fits, restores normal behavior for a modest price.
• Selling or passing it on
  Back up, sign out of accounts, remove the SIM and factory reset. An S21+ with a good screen still has resale value, and a battery replacement before selling raises it.
• Battery replacement
  A new battery is the best investment for an S21+ you want to keep. Samsung's service centers and many repair shops fit one, and the phone will last a day again. Check that the shop uses a genuine cell and keeps the water seals intact, since a poor repair can cost the phone its resistance.
• Is repair still sensible
  An S21+ with a cracked screen or tired battery is a candidate for repair only if the rest of the phone is sound. The phone is past its updates, so a repair buys you a working phone but not new features. Compare the repair quote with the price of a newer used Galaxy before deciding.
• Accessories that suit it
  Cases for the S21+ are widely available, but check the model, since the S21 and S21 Ultra differ. A tempered protector made for an ultrasonic fingerprint reader keeps the reader working, and a USB Power Delivery adapter with a good cable charges at up to the phone's limit. A wireless pad works, and a battery replacement from Samsung keeps the phone going. Samsung Members also offers free diagnostics for the screen, sensors and battery.

Manufacturer support for this product line. Samsung Support — Mobile device support. Official Galaxy model manuals, diagnostics, updates and repair support.

Also read for this model. Samsung Support — Samsung Support.