Start with a clean baseline
Use browser-visible screen, touch, camera, microphone, speaker, sensor and connection tests as a fast functional inspection, then use the OS/manufacturer for battery-health, cellular, biometric and internal hardware diagnostics.
Live evidence
Relevant checks
Battery Runtime CalculatorEstimate runtime from battery watt-hours, average load and conversion efficiency.
→Microphone Level TestSee a live input level meter and identify audio that is too quiet or clipping.
→Data Transfer Time CalculatorEstimate ideal transfer time from data size and an entered link rate.
→First sequence
Do the high-signal checks before risky changes
- 1
Confirm recording format and card capacity
- 2
Test standalone recording before USB-audio mode
- 3
Use a known-good supported card for intermittent recording problems
Decision points
What the result should change
If touch/camera/audio works in browser but not one appCheck the app's permission and selected input/output before resetting the phone.
If charging is the symptomSeparate adapter wattage, cable capability, connector condition and battery/thermal limits.
If the device is used/refurbishedTest all user-facing functions before account transfer/payment, not after.
Browser can help check
- Estimate runtime from entered battery and load values
- Test a browser-visible microphone path when the recorder supports USB audio
- Estimate transfer time
Browser cannot prove
- Read recorder preamp or self-noise electronics
- Test SD-card bus stability inside the recorder
- Repair firmware
Repair boundary
Know when to stop browser troubleshooting
- Swollen batteries, exposed cells or severe heat require immediate service handling.
- Do not insert metal objects or liquids into charging ports.
- DeviceOK cannot verify IMEI ownership, activation lock or water-resistance integrity.
Used-device inspection
What to verify before paying or signing off a repair
- Touch across the whole panel and pixel/color inspection
- Front/rear cameras, microphones, speakers and buttons
- Charging/data port, Wi-Fi/Bluetooth and manufacturer battery-health screen