Repair tools
16 tools that run in your browser. Nothing to install, nothing uploaded.
Repair-or-replace calculators for the moment a device starts failing. A browser cannot read your hardware directly, so these do the arithmetic on figures you read from your own system report — battery capacity, for instance — and turn them into a clear health percentage. The result is the evidence for whether a repair is worth it, framed around fixing first and replacing only when the numbers say so.
- Battery Health EstimatorWork out your battery’s real health from its capacity figures.
- POST Beep Code ReferenceLook up what a POST beep pattern means, and what to try first.
- Full Diagnostic Report ExportEvery silent check in one run, exported as a dated PDF for tickets, claims and resale.
- Game Crash Log InterpreterFind the likely culprit in a game crash log.
- IMEI Checksum ValidatorCheck whether an IMEI is internally valid before you trust a listing.
- Mac Startup Symbol ReferenceWhat each Mac startup symbol means, and which stage of boot it points at.
- Repair Cost EstimatorTotal a repair quote and compare it against buying new.
- Repair vs Replace CalculatorCompare a repair quote with a replacement on cost per remaining year.
- Laptop Screen Flicker TestCheck for PWM backlight flicker — and turn the brightness down first, which is the part people miss.
- Screen Ruler (px/cm/inch)An on-screen ruler you calibrate, so it is actually accurate.
- Screw & Driver Size ReferenceWhich screwdriver a device actually takes, and why the wrong one strips the head.
- Touchpad / Trackpad TestTest what a touchpad can actually show a web page — and know what it cannot.
- Used Device Buying ChecklistThe fifteen checks worth doing before handing over money for a used device.
- Device Info / Spec ReportEverything this browser reports about your device — and what it cannot see.
- Phone Model IdentifierA best guess at your device, and an honest account of the limits.
- Windows Error Code LookupDecode a Windows error code and see what actually causes it.
The arithmetic behind repair or replace
The decision people find hard is usually easy once it is expressed as cost per remaining year of service. A £180 repair on a laptop with an expected three years left is £60 a year; a £700 replacement with six years ahead of it is £117 a year, and the repair wins on the numbers even though the total is smaller in a way that feels like the lesser option. The calculator makes both figures explicit, along with the point where a quote stops being worth accepting — commonly around half the price of an equivalent replacement, sooner if the device has other components at the same age and the same wear.
Battery health comes from your own report, not from the browser
No web page can read your battery. What it can do is the arithmetic on two figures you read from your own system: full charge capacity against the design capacity the battery shipped with. The ratio is the health percentage every native tool reports, and it is worth knowing the shape of a normal curve before reacting to it — most lithium-ion packs sit around 80% after a few hundred cycles, which is expected wear rather than a fault. Below roughly 70%, runtime complaints are usually genuine, and a swollen pack is a safety matter to act on immediately regardless of what the percentage says.
Checking a used device before the money changes hands
The screening pass that catches most expensive surprises takes about ten minutes and needs nothing but a browser. Look at a fullscreen white and a fullscreen black for dead and stuck pixels and for backlight bleed, exercise every key including the modifiers, click each button repeatedly watching for a double-fire, test the trackpad’s multi-touch, and confirm the camera and microphone enumerate. Then ask for what a browser cannot see — the battery health figure from the system report, and the drive’s power-on hours — because a seller who will not produce those is telling you something.
Frequently asked questions
When is a repair quote too high to accept?
The usual rule of thumb is around half the price of an equivalent replacement, but cost per remaining year is the better test. A £180 repair buying three more years costs £60 a year, against £117 a year for a £700 replacement lasting six — so the repair wins despite feeling like the smaller, more temporary option. Adjust downward when other components share the same age and wear, since fixing one is often the first of several.
Can this read my battery health directly?
No — no web page can. The browser has no access to battery capacity data, so these tools do the arithmetic on figures you read from your own system report: full charge capacity against the original design capacity. The ratio is the same health percentage a native tool would give you, and knowing where the figures came from is worth more than a number that appeared without explanation.
My battery reports 80% health. Is that a fault?
Usually not. Most lithium-ion packs settle around 80% of design capacity after a few hundred cycles, which is expected chemistry rather than a defect, and manufacturers commonly warrant to about that level. Below roughly 70%, runtime complaints are genuine and a replacement is reasonable. A physically swollen battery is the exception to every rule here — stop using the device and have it dealt with immediately, whatever the percentage says.
What should I check on a used device that a browser cannot see?
Battery health and drive power-on hours, both of which come from the system’s own reporting rather than any web page, plus the physical things — hinge play, port wear, screen delamination, evidence of liquid ingress. Ask the seller to open the system report in front of you. A seller who will not is answering the question in a different way, and the browser checks you can run are the ten-minute screening pass around that conversation, not a substitute for it.