What Was Happening
A custom-built gaming laptop came into the Putney workshop in July with two complaints written on the same ticket: the Wi-Fi was playing up, and the machine needed its thermal paste changing.
The second complaint arrived with a number attached. In games the frame rate had fallen to around 60 and was sitting there — not crashing, not freezing, just refusing to climb the way it used to. The owner had already reached their own conclusion: the machine was cooking itself and wanted repasting.
That is a more useful starting point than it sounds. A frame counter in the corner of the screen is a diagnostic instrument most computer owners never have, so when a gamer says a number has changed, that is evidence rather than a vague sense that things feel slower.
Two complaints on one ticket still needed separating before anything came apart, because a struggling network and an overheating machine produce very nearly the same experience for somebody mid-game.
Sound like your problem?
Bring it to our Putney workshop or message us a photo and we will give you a straight answer and a quote before any work starts.
Our Diagnosis
The first decision was which of the two complaints explained the frame rate, because fixing the wrong one would have looked exactly like fixing nothing.
A frame rate that settles at a flat 60 deserves care, because 60 is not automatically a bad number. Plenty of machines sit there deliberately — a 60Hz display, vertical sync switched on, or a power profile quietly capping things. The real question is whether 60 is a ceiling being imposed or a wall being hit.
On a machine that had been delivering more, and that its owner already thought was due a repaste, the wall was likelier. Heat produces this pattern precisely: a chip that cannot shed heat quickly enough does not fail, it lowers its own clock speed until the heat it makes matches the heat the cooling system can carry away. That is designed behaviour, and it is silent. No error, no warning, no crash — the machine simply becomes a slower version of itself, and the frame counter is where you notice.
A network fault reads differently. When the connection is at fault the frame rate stays where it was and the game misbehaves instead: half-second freezes, other players skipping about, an action registering a beat late. Heat lowers the number smoothly and holds it there. A poor connection leaves the number alone and breaks the timing.
That set the order of work. Cooling first, because it matched the reported symptom, and because the alternative was rebuilding a network that might have had nothing wrong with it. Opening the machine supported the read: there was dust through the cooling system to clear, and paste that had done its time.
How We Fixed It
The work was an internal strip-down — cooling assembly off, dust cleared, fresh thermal compound where the heatsink meets the chips it cools.
It is worth saying what that is and is not, because “give it a clean” covers two very different jobs. Blowing a can of compressed air through the outside vents is not this. On most laptops the dust that matters has gathered on the face of the fin stack — the dense little radiator between the fan and the exhaust vent — where it mats into something closer to felt than fluff. Air from outside pushes part of it further in. Getting it out means lifting the assembly off the board.
With the fan and fin stack clear, the old compound came off both the chip surfaces and the metal plate that sits against them, and fresh paste went on. Paste fills the tiny air gaps between two surfaces that look flat and are not; air conducts heat poorly, and metal-to-metal contact is never as complete as it appears. Quantity matters in both directions — too little leaves voids, too much stops it pressing out into a thin conducting layer.
Reassembled, the machine went back under load rather than being booted once and handed over. What matters on a cooling job is the tenth minute at full tilt, not the first thirty seconds.
The work carries our standard 90-day warranty on the parts and the workmanship. That does not extend to accidental damage, and it is not a promise the machine will never run warm again.
The Result
The laptop went home with its cooling system doing the job the chassis was designed around, and the heat ceiling that had been holding the frame rate down lifted with it. It was a workshop job with nothing to order, which is the good news about a clean and repaste generally.
We were straight about the other half of the ticket. A dust clean and a repaste are not a Wi-Fi fix. If the wireless trouble continued once the machine was running cool, that was a separate piece of work with its own diagnosis, and it would start at the router and the wireless environment rather than inside the laptop.
Why This Happens
Gaming laptops sit at the sharp end of this. They run high-power components inside a chassis two or three centimetres thick, and the entire design assumes air moving freely through a small heat exchanger. There is very little margin built in, so anything restricting the airflow shows up in performance quickly — in a way a low-power office laptop with an idling fan would shrug off.
Dust is the usual cause and it builds faster than people expect. The fan pulls room air through the machine every minute it runs, and whatever the room contains goes with it: carpet fibres, pet hair, the general grey fluff of an indoor flat. It collects at the first dense obstacle, which is the fin stack, and forms a layer across the face of it. The fan then labours against a surface air can no longer pass through, which is why a machine in this state often sounds as though it is cooling itself furiously while doing very little of the sort.
Thermal paste is the other half of the story. It is a consumable, not a permanent fitting, and repeated heating and cooling dries it out until it stops filling the gaps it was put there to fill — typically inside three to five years, sooner on a machine that spends its evenings at full load. Neither of these is a fault in the sense of something breaking; both are maintenance falling due, and neither announces itself. The decline is gradual and easy to blame on a game update, a Windows update or the broadband.
Telling a Slow Connection from a Hot Laptop
Since that is what this ticket turned on, here is how to separate the two at home before anything gets opened up.
- Play something offline. If a single-player game with no network involvement shows the same drop, your connection is not the problem.
- Watch the shape of it. Steady but lower is the machine. High but jumping — rubber-banding, brief freezes, other players teleporting — is the connection.
- Time it. Thermal limits take a few minutes to arrive. Fine for ten minutes and then degrading is heat almost every time; network trouble does not wait for the machine to warm up.
- Test with a cable. An ethernet run to the router settles it in one step. If the stutter goes but the frame rate is still capped, the machine is the problem. If everything comes right, the wireless is.
- Check the other devices. If phones and TVs on the same Wi-Fi struggle at the same moment, the laptop is a witness rather than the culprit.
If the answer lands on the network side, the fixes are different ones — where the router sits, which band the machine joins, congestion from neighbouring networks in a block of flats, or coverage that needs extending properly rather than patching.
Local Help in Putney SW15
If a laptop has quietly got worse at the thing it was bought for — games, video editing, anything that loads it for more than a few minutes — a cooling service is worth ruling in early, well before replacing parts or replacing the machine.
We will also tell you when a clean will not get you what you want. Some thin gaming builds were thermally marginal the day they left the factory, and a repaste restores the cooling they were designed to have rather than giving them more. Dust comes back too, so this is maintenance on a cycle of a year or two rather than a permanent cure. On an unbranded custom build there is one more caveat: if a fan is worn rather than merely dirty, finding the exact replacement for a chassis carrying no model number can be the hardest part of the job.
Our workshop is in Putney, and a diagnostic fee applies which is absorbed into the repair if you go ahead. If the trouble turns out to be the network rather than the machine, we can look at that too — see network setup in Putney or call 020 7610 0500.
