How We Find Motherboard Faults With Thermal Imaging

Diagnostics & Repair

A look inside advanced diagnostics — how an infrared camera turns invisible faults into something you can actually see and fix.

Fixfactor Team 8 min read

When a laptop or phone stops working without any visible damage — no cracked screen, no liquid spill the owner remembers, no drop — the first job is not to guess. It is to follow a consistent diagnostic strategy that eliminates possibilities one by one.

The obvious things get checked first. Is the battery holding charge, or has it degraded to the point where it is blocking the device from powering on? Is the charging port damaged or clogged with debris? Is the power adapter actually delivering power? Are external modules like the display cable, keyboard flex, or dock connector causing the issue? These are all common failure points that can mimic a dead device, and they are relatively straightforward to test and rule out.

But once you have eliminated the battery, the charging circuit, the display, and other replaceable modules — and the device still will not power on, or crashes, or behaves erratically — the problem is on the motherboard. And that is where diagnostics becomes genuinely difficult. A modern motherboard contains hundreds or thousands of components, most smaller than a grain of rice, and the fault could be in any one of them.

For years, the standard approach at this stage was methodical probing with a multimeter — a handheld tool that measures electrical signals like voltage and resistance. The technician works through the board point by point, comparing readings against what the circuit diagram says they should be, trying to narrow down where the signal breaks. It works, but it is slow. Diagnosing a complex motherboard fault this way could take an hour or more before you even identified the failed component.

Thermal imaging changed that. Not by replacing the multimeter — that is still essential — but by giving us a way to see the fault before we start probing. Power the board on, point the camera, and within seconds the problem often reveals itself as an abnormal heat signature.

How a thermal camera actually works

Every object above absolute zero emits infrared radiation. The warmer the object, the more radiation it emits. A thermal imaging camera has a sensor that detects this radiation and converts it into a visual image, mapping temperature differences to a colour scale — typically from cool blues and purples through greens and yellows to hot reds and whites.

The cameras used in electronics repair are not the same industrial models used for building inspections. They need higher resolution at very close range to distinguish individual components that are millimetres apart. A good board-level thermal camera can detect temperature differences of less than 0.1°C across a motherboard surface — enough to spot one failing component among hundreds of identical-looking ones.

What makes this powerful for diagnostics is a simple principle: electricity flowing through a component generates heat. A healthy component generates a predictable amount of heat for the work it is doing. A faulty component — one that is shorted, partially failed, or operating outside its specifications — generates heat that does not match what it should.

What we actually see through the camera

In practice, thermal imaging in electronics diagnostics falls into a few distinct patterns. Each one tells a different story about what has gone wrong.

Short circuits

A short circuit happens when electricity finds a path it was never supposed to take — essentially a wrong connection on the board. The component where the short occurs draws far more power than it should and heats up rapidly as a result. Through the thermal camera, it lights up immediately when power is applied — often within one to two seconds. On a board where most components are sitting at room temperature, a single bright hot spot is unmistakable.

This is particularly useful for liquid damage cases. When water or other liquids get inside a device, they can cause corrosion that creates short circuits across multiple points on the board. Thermal imaging lets us see exactly which components are affected, rather than painstakingly probing every connection in the damaged area.

Overheating power regulators

Every motherboard has a set of small components called voltage regulators. Their job is to take the power coming from the battery or charger and convert it into the precise voltages that the processor, graphics chip, and memory need to run. Think of them as translators between the power supply and the parts that do the actual computing.

These regulators generate heat during normal operation — that is expected. But when one runs significantly hotter than the ones next to it, or hotter than its workload justifies, it signals a problem. The regulator itself may be failing, or it may be working overtime to compensate for another component nearby that is partially shorted and pulling more power than it should.

Through the camera, healthy regulators appear as a uniform warm area. A failing one stands out — noticeably brighter than the rest, sometimes 20 to 30 degrees above what its neighbours are running at under the same conditions.

Dead components

The reverse pattern is equally useful. When a component that should be active stays cold while everything around it is warming up, that tells us it is either not receiving power or has failed entirely. If the processor remains at room temperature when the board is powered on, while the power delivery components around it are working and warming up normally, that points directly to a dead chip or a broken connection between it and the board.

This “cold spot” diagnosis is very difficult to achieve with a multimeter alone. You would need to know exactly which measurement points to check and what values to expect — which requires detailed circuit diagrams that are not always available, especially for newer devices. The thermal camera gives you the same information visually, in seconds.

The experience factor: knowing what “normal” looks like

A thermal camera is a diagnostic tool, not a diagnostic answer. It shows you temperature data — interpreting that data requires experience and knowledge of how boards behave when they are working correctly.

Every motherboard has its own thermal personality. When a MacBook Pro board powers on, things happen in a predictable order: the chip that manages power distribution warms up first, then the processor and its voltage regulators, then the memory, then the storage controller. There is a predictable sequence and a predictable temperature range for each stage. After seeing hundreds of the same board, you develop an instinctive sense of what “right” looks like — and deviations from that pattern immediately stand out.

For example: on certain MacBook models, it is normal for the area near one of the port controller chips to run warm even when the laptop is idle. A less experienced technician might flag this as a fault. Someone who has worked on that board many times knows it is expected behaviour and would look elsewhere for the actual problem.

The same principle applies in reverse — knowing that a particular component should not be generating any noticeable heat when the device is just sitting there powered on. When it does, that is diagnostic information that only becomes useful if you know the baseline.

What temperatures actually mean

Context is everything. The same temperature reading can be perfectly normal or deeply concerning depending on the component, the operating state of the device, and the ambient conditions. Here are some general patterns we work with during diagnostics:

These are working guidelines, not absolute rules. Different board designs, different chips, and even room temperature all affect the baseline. The point is pattern recognition: something is hotter or colder than it should be, relative to everything else on the same board.

How much faster does it actually make diagnostics?

This depends on the type of fault. For some problems, thermal imaging reduces diagnostic time dramatically. For others, it plays a supporting role alongside traditional methods.

For short circuits, the improvement is most dramatic. What previously required feeding a small amount of power into a circuit and then measuring every component along it one by one — a process that could take 30 to 60 minutes — now takes seconds. Power the board, point the camera, and the shorted component reveals itself. You still confirm the finding with a multimeter, but the camera has already told you where to look.

For intermittent problems — devices that crash under load or freeze randomly — thermal imaging offers something the multimeter cannot: real-time, continuous observation. You can watch the entire board while the device runs, and see exactly which component starts behaving abnormally at the moment the fault occurs. Catching an intermittent fault with a multimeter means testing the right spot at the right time, which involves a lot of luck or a lot of patience.

Can you diagnose motherboard faults without thermal imaging?

Yes. Technicians diagnosed and repaired motherboards long before thermal cameras became affordable for small workshops. A multimeter, circuit diagrams, logical reasoning, and experience are still the foundation of component-level diagnostics. Many faults can be identified through careful electrical measurements without ever using a thermal camera.

There are also fault types where thermal imaging is not particularly helpful. Software issues, corrupted firmware, problems with data signals that do not generate noticeable heat, faults that only appear during specific operations — these require different diagnostic approaches entirely.

What thermal imaging provides is speed and visibility. It does not replace other diagnostic methods — it narrows the field so that those methods can be applied more efficiently. Think of it as the difference between searching a dark room with a torch versus switching on the light. You could find what you are looking for either way, but one approach is significantly faster.

Beyond laptops: phones, tablets, and other devices

Everything described above applies equally to phone and tablet motherboard diagnostics. In fact, thermal imaging is even more valuable for mobile devices because their boards are denser — more components packed into a smaller space. On a modern iPhone or Samsung motherboard, components are stacked and layered, making visual inspection difficult even under a microscope. The thermal camera sees through the density — heat does not hide behind other components.

We use thermal imaging across all device types that come through the workshop: laptops, phones, tablets, game consoles, drones. Any device with a circuit board that handles meaningful power can benefit from thermal diagnostics when something goes wrong at the component level.

Accurate diagnosis leads to the right repair at the right cost

At Fixfactor, thermal imaging is one of several diagnostic tools we use for every advanced repair. Alongside microscope inspection, multimeter testing, and specialised diagnostic software, it helps us build a complete picture of what has gone wrong — and what it will take to fix it.

This matters because accurate diagnosis determines the repair approach. A board fault that looks like a total failure might turn out to be a single shorted capacitor — a tiny component that costs pennies and takes minutes to replace once you know which one it is. Without proper diagnostics, that same device might be written off as beyond repair, costing the owner hundreds of pounds in unnecessary replacement.

Every device we receive goes through a structured diagnostic process before we recommend a repair. We believe the time invested in diagnosis is the most important part of any repair, because it leads to the right solution — and the right cost — for each situation.