Buying & Selling Used Tech? Ensure Your Data is Wiped and Hardware is Flawless

With the skyrocketing prices of flagship iPhones and MacBooks, buying used tech on platforms like Craigslist, eBay, or OfferUp is more popular than ever. However, it’s a gamble. You might end up buying a stolen device with an activation lock, or you might sell your old phone leaving sensitive personal photos recoverable. Use this Ultimate Used Device Checklist to protect your privacy and your wallet.

🔒 Part 1: “Selling My Phone” — The Ironclad Data Wipe

Simply hitting “Erase All Content” isn’t enough in the era of cloud syncing.

• Step 1: The Essential Sign-Outs
  • iPhone (iOS): Settings ➔ Apple ID (Your Name) ➔ scroll to bottom and tap Sign Out. This disables the crucial “Find My” activation lock.
  • Android (Samsung/Pixel): Settings ➔ Accounts ➔ perfectly remove all Google and Samsung accounts.
• Step 2: Break Bluetooth Pairings
  • “Forget” all saved accessories like AirPods, Galaxy Buds, or Apple Watches to prevent your phone from automatically linking later.
• Step 3: Factory Data Reset
  • Only after logging out, perform the final factory reset.
  • Pro-Tip: To defeat forensic data recovery, fill up your phone’s empty storage space with dummy massive video files before performing the wipe. This overwrites your old data segments securely.
• Step 4: Cosmetic Cleanup
  • Wipe down the screen and edges with an alcohol swab. A clean phone gives buyers confidence and strongly defends your asking price against low-ballers on OfferUp.

🔎 Part 2: “Buying a Used MacBook/Phone” — Hardware Inspection

Never hand over the cash or Zelle someone before performing these on-the-spot tests.

📱 Smartphone Walkaround Inspection

• IMEI Carrier Check (Stolen/Blacklisted?): Find the IMEI number (*#06#) and run it through a free online IMEI checker (e.g., Swappa IMEI check or your carrier’s website) to ensure the phone is not reported lost, stolen, or still under an unpaid contract.
• Battery Health:
  • iPhone: Settings ➔ Battery ➔ Battery Health & Charging. (Expect to spend $90+ on a replacement if it’s nearing 80%).
• Display Burn-In & Dead Pixels: Open a pure white image or blank notes app at full brightness. Look closely for faded “ghost” shadows of keyboards or standard apps burned into the OLED screen.
• Functionality Speed Run:
  1. Eject the tray and pop in your own SIM card to confirm cell reception and 5G/LTE data.
  2. Test front/rear cameras, focusing, and ultra-wide lenses.
  3. Click all physical volume keys and the mute switch.
  4. Play a YouTube video at max volume to check for blown speakers.

💻 MacBook / Laptop Inspection

• Battery Cycle Count:
  • Mac: Hold ‘Option’ ➔ Click Apple Logo ➔ System Information ➔ Power ➔ check “Cycle Count”. (Under 300 is usually great; over 800 means replacement is imminent).
• Keyboard & Trackpad Dead Zones: Open a text editor and literally tap every single key—especially the corners & spacepad. Drag a file across the entire screen using the trackpad to ensure zero dead spots.
• Hinge Integrity: Open the laptop lid to 45 degrees, then 90 degrees. If it flops down or feels overly loose, the internal hinges are compromised.