thermal pad/paste for laptop GPU & capacitor?

[kobrrra]

I had to change a failed motherboard for a HP Pavilion dv4 laptop. I am using the heatsink & cpu from the dead mobo.

I have applied Arctic Silver 5 to the CPU. Do I need to change the “brown pad” that sits on the GPU? Another “green” one looks like a pad/paste and sits on two blocks (capacitors?). Does that need to be changed as well?

What kind of replacements would I need and where should I look for them? HP provides pads & paste with its fan/heat sink/mobo/CPU spare parts kit but it’s very expensive.

From the HP Maintenance & Service guide:
“Each time the fan and heat sink are removed, the thermal material must be thoroughly cleaned from the surfaces of the heat sink and system board components: heat sink (1), processor (2), Northbridge clip (3), and capacitor (4). Thermal pads and thermal paste must be installed on all surfaces before the fan and heat sink are reinstalled. Thermal pads and thermal paste are included with all fan, heat sink, system board, and processor spare part kits.”

sorry if i have posted this in the wrong category. thanks for looking.

 

[stahlhart]

Welcome to the AnandTech forums.

From the personal experience of having tried several, this is one of the best (if not the best) you can get for this particular task:

http://www.performance-pcs.com/cata...oduct_info&cPath=46_58_1107&products_id=26246

http://www.frozencpu.com/products/1...und_-_35_Grams_TC-GC-03-A.html?tl=g8c127s1491

I'm guessing that the "capacitors" you've pointed to in the image are actually VRMs, by the way.

 

[kobrrra]

thanks for the suggested links. i had a quick look at them. would they fill up the gap completely between the heat sink and the GPU/VRM surface? i think the contact point on the heat sink where it touches gpu is not flat.

 

[stahlhart]

It's difficult to tell from your photo, as it appears that you've already cleaned the TIM from those two surfaces -- or am I misinterpreting what I'm seeing?

What is that narrow strip of lighter color on the bottom edge of the GPU -- is that a reflection, or material on the chip surface?

You'll need to clean both surfaces before applying new TIM -- there are products you can buy for this, or annhydrous isopropyl alcohol (97%) will work also. Make sure whatever you use to clean the surfaces doesn't leave any residue or debris behind.

The TIM is intended to displace air pockets between the two surfaces, as it is a better conductor of heat than air, but it won't correct two surfaces that aren't making correct contact in the first place. You can do an initial trial application of TIM, then remove the heat sink to see if you're getting proper dispersal of the material, sort of like what you're seeing for the CPU surfaces.

 

[kobrrra]

It's difficult to tell from your photo, as it appears that you've already cleaned the TIM from those two surfaces -- or am I misinterpreting what I'm seeing?

What is that narrow strip of lighter color on the bottom edge of the GPU -- is that a reflection, or material on the chip surface?

You'll need to clean both surfaces before applying new TIM -- there are products you can buy for this, or annhydrous isopropyl alcohol (97%) will work also. Make sure whatever you use to clean the surfaces doesn't leave any residue or debris behind.

The TIM is intended to displace air pockets between the two surfaces, as it is a better conductor of heat than air, but it won't correct two surfaces that aren't making correct contact in the first place. You can do an initial trial application of TIM, then remove the heat sink to see if you're getting proper dispersal of the material, sort of like what you're seeing for the CPU surfaces.

the chips had not been cleaned when i took this shot. the pads didn't leave too much residue below on the chips. there was plenty of residue on the cpu though.

the narrow strip of light color on the gpu probably is reflection.

actually i reapplied the same heat sink to a replacement motherboard. i left the pads sitting on the two places. i cleaned the heat sink area above the cpu with ArctiClean and applied arctic silver 5 to the cpu.

i was getting temps like 50 C-70 C after booting. i left it running for two days but the temps didn't go down. the fan blew pretty loud at "some" times. after that i shut it down.

 

[KingFatty]

Those pads are physically deformed once they are installed. So like any deformable thing, you'd be best to replace it with a fresh springy one, that can conform to the surface and make the best contact. Re-using an already-deformed material can result in gaps, because you are unlikely to perfectly align to get the deformation in the perfect location to fit like a glove.

But, as a way to save money, why don't you just use thermal paste on top of the pads? That will fill any minor gaps from slight misalignment, and the already-deformed pads may fill up the rest of the slack.

But don't try to do this with no pads at all - if you use paste-only with no pads, the paste will not properly fill the gap.

I think the best option overall would be to simply order a new set of aftermarket thermal pads. You'll need to figure out what thickness and width, and then also decide on what level of performance to get, all variables you can play around with to find the right price, which should be much cheaper than the OEM set. Plus, you can cut the strips to size that you need, and keep the remainder around as a thermal kit for future use.

 

[stahlhart]

But don't try to do this with no pads at all - if you use paste-only with no pads, the paste will not properly fill the gap.

I didn't realize this -- thanks for the clarification.

I did this work on my wife's laptop, and on hers there was TIM on both the CPU and GPU surfaces. The Gelid compound dropped her CPU temps by about 10C.

I can see now where the gap can be an issue here, as judging by the photo there isn't as much mechanical pressure for the VRM and GPU contact surfaces.

 

[Face2Face]

I would grab this to put on the GPU and the VRM. Fujipoly is awesome stuff.

http://www.frozencpu.com/products/1..._05_-_Thermal_Conductivity_110_WmK.html#blank


This is a .5mm pad, you may need 1mm, just gonna have to measure it or eyeball it. This stuff is like play-doh so going to 1mm shouldn't hurt.

Then use decent thermal compound for the CPU

 

[DAnny b]

You shouldn't replace thermal pads with paste. Thermal paste is too thin to cover the gap that is created when you remove the thermal pad. However there is a paste that can replace pads. It's name is k5 pro. The reason it can replace em is because it is made to be thick.
I have used it about a year now for my laptop and desktop and so far they both keep good temperatures.
Hope this helped