Laptop thermal paste, liquid metal and PTM7950 replacement

When it’s time for new paste

• High temperatures: the processor or graphics chip goes over 90 °C even under light use.
• Loud fans even when you’re just reading the news or typing.
• Slowing down after a few minutes: a game or render starts out fine, then everything bogs down. That’s throttling: the processor and graphics chip lower their clock speed on their own so they don’t overheat.
• The laptop switches itself off under load. Most often that’s overheating protection.

A laptop that has been running hot for years is more prone to graphics chip failure: artefacts appear on the screen, or there’s no picture at all. That calls for a bigger job, graphics card repair.

Cleaning always comes with it

Fresh paste on a heatsink clogged with dust won’t do much. Over time the heatsink fins get covered by a layer of dust that looks like felt, and the hot air has nowhere to go. That’s why a paste change always comes with a full laptop dust clean: we take the heatsink off, clean the fins and fans, and check the fan bearings.

On laptops with a dedicated graphics card, the video memory (VRAM), and often the voltage regulators (VRM) as well, pass their heat to the heatsink through thermal pads. Thickness matters a lot here: a pad that’s too thin doesn’t touch the chip, and one that’s too thick lifts the heatsink and ruins the contact on the processor or graphics chip. So we measure the old pads and fit new ones of the right thickness, not “whatever’s lying around”.

Paste, liquid metal or PTM7950

Thermal paste (Arctic MX-6). The standard for most laptops. It doesn’t conduct electricity, so there’s no harm if a little spreads over the edge of the chip. The downside is that on a laptop’s bare chip, after many cycles of heating up and cooling down, it slowly gets squeezed out from the edges (so-called pump-out) and dries out. On an office laptop that takes years; on a gaming laptop, noticeably less.

Liquid metal (Thermal Grizzly). A gallium-based alloy that is liquid at room temperature. It conducts heat far better than paste, and on powerful chips it usually takes off a few more degrees. But it also conducts electricity: a drop that escapes onto the tiny components around the chip causes a short circuit, and gallium eats into aluminium. That’s why we only apply it to a copper or nickel-plated contact plate on the heatsink. We inspect the components around the chip under a microscope and insulate them, then build a seal that keeps the metal where it belongs.

Some gaming laptops, certain ASUS ROG models for example, come with liquid metal on the processor from the factory. On those we carefully remove the old alloy and apply a fresh layer, because the cooling was designed around it.

PTM7950 (Honeywell). A phase-change thermal pad. It goes on as a thin film, and once the chip warms up to about 45 °C it softens and fills the tiny irregularities between the chip and the heatsink. It doesn’t conduct electricity and doesn’t get pushed out from the edges, so temperatures stay at their post-service level for much longer.

What we recommend for which laptop

• Office, school or thin-and-light laptop: a good-quality paste. Liquid metal won’t make a difference you’d notice there.
• Gaming laptop, rendering, CAD: usually PTM7950, because it lasts. Liquid metal when the heatsink allows it and every degree matters to you.

If liquid metal isn’t safe on your heatsink, we won’t apply it even if you ask for it; we’ll suggest PTM7950 instead.

How we check the result

Once the laptop is back together, we run it under full processor and graphics load and watch the temperatures, clock speeds and fans. If the laptop is working when it comes in, we measure temperatures before the service too, so you can see the difference in numbers. If they still aren’t where they should be after the replacement, we look further for the cause (a fan, a damaged heat pipe) and get back to you before doing any extra work.

How long it takes, and the warranty

It’s usually done the same or the next day when the parts are in stock. Rarer parts we order in, and we let you know the timeframe after the inspection. We fit quality parts that match your model, and the 6-month warranty on the work is written on your service sheet. We are an independent service and use brand names for description only. For other faults, see our laptop repair page.