Good old ASUS GX502GW-XB76 - overheating and thermal pad replacing

[Emin_KN]

Hey guys! I've been experiencing this issue with my Zephyrus S laptop for a while. Namely - overheating and thermal throttling during gaming. The temperatures hit 100 degrees rather quickly according to HWinfo64 and OCCT. 

I tried repasting and changing thermal pads, which helped (kinda) and I was able to reduce the temps to 80ish in CS2 in particular. But this did not last longer than a month until it started overheating again. Repasting did not help this time somehow. 

So long story short - does anyone know by chance what is actually the correct thermal pad thickness for this particular laptop model? I mean for VRMs and VRAMs around the GPU and CPU dies. I've been using 1 mm thick pads which seemed a bit too thick in the beginning. Now I'm using 0.5 mm thickness, but it does not seem to help. Trying to grab every opportunity here...

Cheers and thanks in advance!

[ElectroStingz]

Hello,

Use thermal putty instead of thermal pads, this is what's used for most modern laptops,

https://www.thermal-grizzly.com/en/tg-putty/s-tg-p-b-030

You apply the required height like 0.5-1.0mm over what you need so that when you press the heatsink down it will squish the excess out to provide the perfect height and good contact all round including the edges of the chips / mosfets.

For thermal paste used something long lasting such as MX-6 or Thermal Grizzly Duronaut.

But your temperatures, are they the result of overheating or the CPU boosting high? (high boost usually comes with a higher temp)

https://www.electrostingz.com/2025/06/how-to-check-laptop-cooler-performance-intel/

[Emin_KN]

Thanks for the feedback Electrostingz! 

I've been using the Gelid GP extreme thermal pads all this time, but will try thermal putty instead as you suggested. The paste that I am using is MX-6 (used MX-4 before), so this should be fine.

Regarding your question - I am mostly using two power regimes on my laptop - one (silent) when working and watching stuff online, and another one (turbo) when gaming (it switches automatically via scenario profiles in Armoury). So basically when it goes to Turbo mode (which does boost CPU of course) during gaming, that's when it starts overheating, reaching 100 degrees celsius. Right now, the CPU is rather hot too, despite being in the silent mode (somewhere between 65-70 celsius), which is much higher than I would expect. The cpu boost in the turbo mode is just a standard thing I suppose, the cpu and gpu frequencies are just standard.

I've read somewhere that certain heatsink imperfections can also cause uneven heat distribution, but as far as I can see there are no visible deformations on my heatsink...

[ElectroStingz]

How do things compare when the laptop was new (if you had it from new?)

Heatsink efficiency / heatpipes degraded, can happen.  If you are able to run the laptop without the rear casing try some games then touch the heat pipes and see if they are all warm / similar temps. An Infrared thermometer would be better for this.

Also when you take the heatsink off can you take pictures of the CPU / GPU and heatsink CPU/GPU base plate so we can see how the thermal paste has distributed across both sides.

[Emin_KN]

Sure, I will disassemble in a couple of days probably, and upload all the pics here. thanks for offering this!

Regarding the initial performance of the laptop - it was actually fine in the beginning (and yes, it was new). I don't know what the initial idle and turbo regime temperatures were at the beginning, as I never had any issues and basically never checked. I started noticing higher temperatures a couple of years later. I also had to substitute one of the fans, because mine just started getting jammed from time to time for whatever reason until it stopped completely. So I also did the first repasting and also changed some of the thermal pads. Then it was alright again for a while. After I had started noticing overheating last year I thought the problem was with the thermal pads and that I just used wrong pad thickness (1 mm at that time). But then I put new gelid pads (0.5 mm) and the problem kinda was resolved for a while. You know the rest of the story 🙂 I actually also experimented a bit in the meantime, adding different amounts of thermal paste/different patterns even. I guess I can already disassemble this thing with my eyes closed and hands behind my back 😄 

[Emin_KN]

Hi again ElectroStingz,

here is the photo, as discussed. Some of the thermal pads are missing on this picture, but they are simply stuck on the backside of the heatsink, so no worries 🙂 Regarding the thermal paste, what I noticed is that the paste in the middle of the GPU die got hardened (probably from overheating) and that just within a week after repasting. Do you see anything else peculiar/not normal here? 

[ElectroStingz]

Looks to thick and like it didn't spread out well when the heatsink was screwed down, likely the pad's causing this.

See here the right side with copper base plate, this is how thin the layer should look on the GPU / CPU DIE

And here the GPU DIE, the layer of thermal paste should be this thin after the heatsink is attached and removed.

If the screws were all fully tightened it has to be the thermal pads they can increase the height sometimes so you never get good contact on the CPU / GPU. (The blue stuff is thermal putty). 

[Emin_KN]

Wow that's way less thermal paste that I would've expected tbh. Ok I guess the last option I have is to remove the thermal pads, use thermal putty instead and also less thermal paste. Will order the putty from amazon today, I guess it should arrive within a couple of days. As I've got no experience with applying thermal putty, can you advise what amount per chip/mosfet should be applied, and if you spread it in advance or just apply a drop in the middle and then spread by screwing down the heatsink?

[ElectroStingz]

Various methods, you can spread the putty over the VRM and MEM chips so you get a good base layer, then do a 1/4 blob in the middle of each chip / mosfet / coil, so that when you press the heatsink it will squish out.

And check before applying thermal paste, so do the putty, attach heatsink, take off and see how good your putty contact is, if all ok just add a tiny 1/4 blob again or less (you will need to judge this as it's dependent on the gap its trying to fill)

1/4 blob means 1/4 the size of the area you are applying it to, so for a memory chip 1/4 the area, blob in the middle. For mosfet / coil its tiny once you have that base layer.

Alternatively you can just do blobs on each part and as long as you are over the height required so that the when the heatsink is down it will squish out it's good too. But for a new application like if you are not fully sure on the heatsink it's always best to check prior to applying thermal paste.

This one can be messy so you'll be ok, just be reasonable and don't go excessive.

[Emin_KN]

thank you man, appreciate your help a lot! I guess if I this also does not fix the issue, then the only possibility left will be a problem with the heatsink itself (like if it's bent somewhere for example), or I don't know )