Guides
Last updated
Each guide goes with one of the free tests on this site. Some answer "is my score good?" with real numbers, including anonymous results from people who took the same test on Testnook. Others walk through a fix, step by step, for hardware that is acting up: a drifting stick, keys that do not register, a webcam or microphone the computer cannot find, dead pixels, screen burn-in.
Every guide starts with a short answer, then explains the why. Where a test can show the problem, there is a link to run it in your browser first, so you know what you are fixing before you open a settings menu or a screwdriver.
Keyboard Tests
Mouse Tests
- Mouse Double Clicking on Its Own? Causes and FixesConfirm the switch is bouncing, then fix it with settings, cleaning or a new switch.
- Mouse Polling Rate Explained: 125 vs 1000 Hz and UpWhat polling rate is, how 125, 1000 and 8000 Hz differ and which one to pick.
- What DPI Should I Use? Mouse DPI for Gaming and WorkGood DPI settings for shooters, other games and desktop work, and why higher is not better.
Controller & Gamepad Tests
Screen & Monitor Tests
- Backlight Bleed: How to Test It and Fix ItTest for backlight bleed the right way, tell it from IPS glow and know when to return a screen.
- Dead Pixel vs Stuck Pixel: How to Tell and How to FixBlack is dead, coloured is stuck. Which ones can be fixed, and when a screen qualifies for replacement.
- Is 144Hz Worth It? 60 vs 144 vs 240Hz ExplainedWhat refresh rate changes, who notices it, and how to check yours really runs at 144Hz.
- OLED Burn-In: How to Fix It, and How to Prevent ItRetention clears, burn-in does not. What pixel refresh does, and the habits that prevent it.
Audio, Speaker & Mic Tests
Webcam & Camera Tests
Reaction & Speed Benchmarks
Phone Tests
- Auto-Brightness Not Working? How to Fix Adaptive BrightnessWhy adaptive brightness gets it wrong and how to reset it, from a covered sensor to a learned curve.
- Auto-Rotate Not Working? How to Fix Screen RotationWhy the screen stops rotating and the fixes to try in order, from the rotation lock to a sensor test.
- Battery Health Explained: What the Percentage MeansWhat maximum capacity and charge cycles mean, when to replace a battery and how to slow wear.
- Gyroscope vs Accelerometer: What Each Sensor DoesWhat each motion sensor measures, why phones combine them and how to tell if yours has a gyroscope.
- How to Calibrate Your Phone Compass (Android and iPhone)The figure 8 calibration, the settings that help, what throws a compass off and how to check it worked.
- How to Clean a Phone Speaker SafelyGet water, dust and lint out of a phone speaker without damaging it.
- How to Improve GPS Accuracy on Your PhoneThe settings, habits and checks that bring phone location accuracy down to a few metres.
- How to Test a Used Phone Before BuyingA 15-minute checklist for any second-hand iPhone or Android before you hand over money.
- Proximity Sensor Not Working? Fixes for Calls and Black ScreensWhy the screen stays on at your ear or stays black, and the fixes to try before a repair.
Memory Tests & Games
Typing Tests
Eye & Vision Tests
- Astigmatism Explained: Symptoms, Causes and CorrectionWhat astigmatism is, how to spot it, how to read CYL and axis, and how it is corrected.
- Types of Colour Blindness Explained (With What Each Looks Like)Red-green, blue-yellow and total colour blindness: how common each is and what each looks like.
- What Is 20/20 Vision? Visual Acuity ExplainedWhat 20/20, 6/6 and other eye chart scores mean, and what they do not tell you.