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Laptop heatsink mod?

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Charpy

Registered
Joined
Aug 30, 2011
Hey folks, how are you all doing.

I have an ageing Acer 4535G that I'll be pulling apart soon for a fan replacement. I hate to say it but in the 18 months of owning it this will be the third fan that's getting put in. I got a laptop repair crowd (can't remember who.. Some folks last time I was in Singapore) to replace the factory fan at the 1yr mark. Unfortunately the one they put in it barely even lasted 6 months without the old bearing problems coming back..

I'm now starting to think that there's a design flaw with the thermal module, and it's up to me to try and fix it or prolong the next time I have to go replacing things.. My thinking is that the less the fan runs, the better, so doing some heatsink modding to increase passive cooling would be a good idea.

While I have no qualms with stuff like building and pulling apart systems, I've never actually modified factory or aftermarket parts before, let alone those for a lappy. I admit I'm a little unsure whether my plans for this little job of mine are alright or not. Hence, I made this account to tap the minds of those greater than I for advice and inspiration. :D

Basically the idea is to (aside from replacing the fan, of course) remove the stock aluminum base(?) from the CPU/GPU and grind down these little circular burs outside the fan shroud, placing cheap copper ramsinks on top of the now flat surface. While I'm at it I might put a couple ramsinks directly on the heatpipe in a couple places where there is room, but all this leads to a few questions:

  1. Is the effort of grinding down the factory burs and making this weird combination alu/copper heatsink worth it? I know those burs are to increase surface area, but they just seem like some afterthought by the Acer design team. The things are too shallow and widely spaced IMO to have any significant heatsink effect (there is space BTW), and they don't even cover the whole flat side around the fan shroud. On the other hand, could the alu/copper connection that Ill be making be worse than the stock design? If anything I'll be adding more mass, but I'd like peoples opinions on this.
  2. Will putting ramsinks directly onto the heatpipe have a beneficial effect, specifically if they are put somewhere towards the middle of the heatpipe length? I've looked a little into how heatpipes work, but my search-fu is low. The main page I've looked at describes heating and cooling 'ends', and my fear is that I might screw up the circulation of the internal fluid and actually make the pipe's cooling efficiency worse.
  3. I'm humming and harring between using the the thermal tape coming with the ramsinks or using AS5 with superglue in the corners. Which would be better for heat transfer? Once they're on I'm not intending to take them off, so the permanence of the superglue isn't an issue..

Well.. that's the main points I wanted to ask, but is there anything else that might be useful to know/do or potential issues that am overseeing? All the parts I need are are already ordered and (apparently) posted, so it's just a matter of time before my little mod starts!

Oh, and my apologies if this more suited to the cooling or laptop sections. A quick browse through there though didn't find anything like what I'm planning to do, and I also wanted to go to where the expert hardware modders are! :comp:
 
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You would benefit by just changing the TIM to AS5, and burning it in for 100 hours to cure it... Temps may go down a few Celsius. But other than that, you're just re-inventing the wheel where engineers put alot of effort in designing in the first place...:thup:
 
Hi bag-o-doughnuts and thanks for the reply.

Under normal circumstances I would agree with you and stop just at changing the TIM - I'm sure that the massive globules of paste the manufactures put on when slapping these things together wouldn't be the best for heat transfer. However, as I've said, I had a repair shop change the fan once before. I'm honestly not sure whether those people changed the TIM then as part of the service (they better have - I paid them enough heheh..).

Due to this uncertainty, I'm going with the assumption that the TIM has already been changed once and is not stock. If I find out though that it hasn't when I pop the thermal module off, it'll be a few bonus degrees of cooling. :D

Additionally, the aim for me is to bring down the temps as much as possible, with I suppose the restriction of not resorting to drilling massive holes in the case or making it not portable. I understand your comment on my reinventing the wheel, but isn't that sort of what alternative modding is about? (though I probly would use 'replace' or 'improve upon' rather than reinvent :D)

*Hopes he did not step on any toes*
 
Laptops are difficult to mod without a machine shop at your disposal. Replacing the fan is simple as going on e-bay and getting one, with heat pipe and all... Not really much you can do other than changing the TIM...
 
As has been said there's nothing much to be done apart from changing the TIM, usually laptops just use a thermal pad or tape. I'm going to strip down my Dell D630 soon and apply some MX-2 as I was video encoding with handbrake the other day the CPU hit 90c! I stopped encoding and have only used the machine for light use ever since till I can be bothered to strip it down.

Makes me wonder how hot things got when playing CS:S since the heatsink cools the CPU, NB and GPU!
 
Lube the fan. My gf's laptop fan needs to be lubed once a year or so. So far ATF (automatic transmission fluid) has lasted the longest.
 
90C for laptops isn't too horrible. Not great, but not too bad. Chances are the fan wasn't going flat out when you saw that... my 6910p can hit 85C under load, but when i'm using the GPU and CPU, it doesn't get past about 70C.
 
I was not able to read the entire post because my att- squirrel!

Do you use a cooling pad, or at least let the laptop run on a solid surface? This may allow cooler temps so that the internal fan doesn't have to kick in as often.

Ramsinks on the heat pipe sounds like an interesting idea (many CPU heatsinks now have fins running the entire length of the heatpipe, so I'd guess there isn't a 'flow' issue), but I would expect it to make the laptop less portable...
 
Hey guys, thanks for stopping by.

Hmm, ok well there's 2 for just changing the TIM 'cause anything else is too difficult. I dunno.. I don't mind difficult, :p but I suppose now I'll just change the TIM over first and see the result before going ahead with ramsinks.. I shall call it plan A and plan B! :D

Max temps for me isn't much of a problem. I remember running prime95 over a year back for giggles (was running a new rig through its paces at the time), and the CPU temps were in the mid-80s after an overnight run. No, what I'm wanting to try and do is to reduce the idle/low load temps so the fan isn't always spinning as soon as a word doc is open, or firefox on a simple webpage. Idle CPU temps recorded last week were ~40C, but as soon as you have a single window up it hangs around the low 50s. Not saying that's bad for temps, but it appears the fan kicks in at 45C, so if I can get 5C off I hope the fan's lifespan will increase a fair bit.

My lappy's always on a solid surface or elevated on a fanless cooling pad. I used to have an old usb powered cooler that was hooked up to an external HDD powerpack (it was loud but MAN did that move air!), but I don't know where that is anymore..

I considered lubing the fan before ordering a new one, but couldn't pull the thing apart to get to the bearing (seems like a fully enclosed unit - there was no opening/circlip at the base). The replaement I'm getting is a different brand, but if that's the same, is there another way of getting into the thing later on without accidentally drowning the motor in oil?

I'm expecting my parts to arrive in the next few days. Oh, and I stumbled upon a thread here talking about lapping. Is this worthwhile to do with the TIM change before considering the ramsinks?

Cheers, and sorry for another long post.. (I tend to do this a lot.. Slowly learning stuff though, so please keep persevering for me :) )
 
I wouldn't lap a laptop heatsink. They're a really really close fit as it stands, and lapping might do more harm than good in pressure loss.

Something else you might be able to do to lower temps just that little bit is try RMClock. It's a program that allows you to edit the clock states, voltages, and what load the CPU has to hit before it goes to the next clock state. I use it on my laptop to help with battery life, and the affect it has on heat is enough to keep the fan off most all the time that i'm web browsing and stuff. (That, or it's doing like 800rpm)
 
Sorry for the late reply... My university decided to have all of my mid term reports and exams due all in the same week, and this weekend I'm down and out with the flu.. Doesn't get any more exiting than this! Haha.. ha.. :rain:

RMClock looks really interesting CompuTamer. I'll have a fiddle round with it soon and see how far I can undervolt my CPU. I'm a bit hesitant to underclock really as my laptop's slow enough as it is on battery. Really turned things down with the windows power options already to the point where even MP3s don't play properly (well.. on WMP at least) unless you're on power!

Reading through the RMclock site, am I correct in thinking that the basic (Free) version doesn't allow you to set multiple settings/profiles?

I finally recieved my replacement fan a few days ago, but haven't yet found the time to put it in and replace the TIM. Chances are I'll post here again in a weeks time to report how things have gone/how temps are once the AS5 is cured.
 
Hey folks, I'm back! The AS5 isn't 100% cured yet, but it's close enough and I said I'd report back in a week. Oh, and I have few pics as well (I have to fuel my ego sense of accomplishment somehow!), along with more questions... :rain:

I guess first off I'll show what was waiting for me after pulling the heatsink/thermal module off the the mainboard:

5xv97r.jpg

Did anybody order some huge freakin slabs of.. of... what the heck is this, paste?

2ceov4k.jpg

Well, I think it's paste.. eyeballing the TIM thicknesses with a ruler shows the gap between the GPU chips and the heatsink is ~1mm. The white thermal pad (middle left of the heatsink module in the 1st image) was slightly less at ~0.75mm gap and was melted/deformed beyond reuse, not that I was planning to.

Now, the first of the main questions.. After cleaning up the old paste off the CPU I see this weird sort of mark or deformation. It might just be excess adhesive that was used during the chip's manufacturing process, but I'd like to know if this is something more serious that I should worry about.. like delamination or something.

2n031wi.jpg

Next question, does anyone know what temperature aluminum tarnishes at? This is what I found after removing the old fan:

314b18n.jpg

The photo really doesn't show just how dark the discolouration is (in person it's almost black), but also note the "ring" where the blades of the old fan have been hitting the heatsink due to the dead bearing. I would've sworn that it was just bits of the old fan getting worn off, but doing a GPU stresstest with OCCT before pulling everything apart showed the graphics temp peak at 95C (using GPU-Z) I'm not so sure.. Should also say that the test was with the CPU at near-idle (which was at ~75C, according to OCCT).

The two possible places where this temp is being recorded is either (looking at the first pic) the upper left chip, labelled with the ATI logo and directly under the heatpipe, or the lower "AMD Radeon" labelled chip in the black plastic, which gets mounted right underneath that square notch that you can see above. I placed my bet that it was under the fan, and decided to fashion copper shims that would not only reduce the 1mm gap, but also try to give a lot more mass and better access to the heatpipe in that area. The shims in the end turned out like this:

1zq6hzk.jpg

Don't start - the hole drilling was a mistake. The idea was to increase the surface area for better heat radiation, but I made a hash of the hole spacing and broke two drill bits in the process. Would've saved a lot of hassle if I had a drill press, or not done it at all. :-/

I found that the GPU contact areas were the same height, so I made a single large shim to cover that whole side. Both the shims and the heatsink were lapped and the whole lot put together with AS5.

2uf3nnl.jpg

It all fit together nicely, though I have a feeling that I may not have remounted the heatsink very level. Despite adding the shim (~0.9mm. I don't think I lapped that much..), I still had a sizable gap and had to use a fair amount of paste to connect the GPU to the chip.. I plan to re-seat it when I find the time. Another thing is I didn't use the ramsinks I ordered yet in case this solution was enough.

Well, GPU temps seem to have gone down a lot. Stresstesting with OCCT gives a peak of 78C (near-idle CPU temp during test @~68C). I didn't get an idle GPU temp beforehand, but now when the CPU is @40C, GPU is ~48C.

Also, CPU temps don't seem to have changed a lot, or perhaps have gotten worse? Before it used to idle @~40C with the fan off, now it idles ~40C with the fan on. After thinking about it though, I didn't do much o that side of the heatsink apart from changing the TIM, and I just increased the GPU's share of the heatpipe.. Also, it's turning summer here in Australia and the temperature has gone up ~9C since I recorded the before temp a fortnight ago (you'd better believe it), so can I tentatively say that this whole thing was successful? How much of an effect does ambient temperature have on air cooling (can I assume a 1:1 increase)?

Apologies for yet another long post (at least it has pictures!), but any extra comments or answers would be appreciated.

P.S. I haven't yet done any undervolting as I can't seem to get RMclock to work for me - the program won't recognise my CPU and the Pstate control options are greyed out. I've done a little searching and have found a similar app called k10stat though, so I'll fiddle with that sometime this week.
 
The free version of RMClock allows multiple profiles :)

The burn-like mark on the CPU is on most mobile chips. My T7500 has it. Not entirely sure what it is, but it's never caused any issues, so i don't worry about it. More than likely what's going with the higher idle temps is the heatpipe is now taking the heat off the GPU and the CPU so it's causing everything to even out to just above the fan cut on point. A small voltage cut was all it took to make my HP 6910p idle and do common work with the fan completely off. It'll come on silently like once every 15 minutes or so, but it's very rare that i ever hear it at all. Even in a silent classroom.

I think for every 1F ambient temp rises, CPU temp rises .8C, so it's closer to a 2:1 rise. This is on desktops though, and there are other factors such as humidity. High humidity cools better because of the moister. Lower humidity cools worse. My laptop pegs out at 68C or so load in a 75F room, but in a 98F day outside, it can get up to that temp at idle with the fan whirring. Max load brings it to 96C ever after new TIM and cleaning it out.

I have NO clue why RMClock won't see your CPU. Did you run it as Admin?


On a side note... your laptop's GPU, Chipset, and CPU are all CRAMMED together. Mine has each one an inch or 2 from each other.
 
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Computamer, I did try RMclock under admin - no difference. Perhaps it's because my CPU is an AMD and yours is an intel? Other than that... the version I was able to get was V2.35 - what's yours?

Also, was that ratio fahrenheit to celsius or celsius to celsius? Don't quite get you.. but assuming a 2C:1C increase for ambient:cpu, the temp improvement (or lack of it) is pretty good, especially considering the change made to the GPU for greater heatpipe access. I'm happy with the change in GPU temps alone, though that wasn't the original aim of the exercise heheh.. ^^

It's a bit hard to measure the chip distances now things are all put back together, but for some sort of reference, the larger shim I made is 80mm long, and 40mm wide without the weird tab I made.
 
acer 4535G

just want to ask if you have guide or manual on disassembling and assembling acer4535G. Had a black screen problem, tried external monitor.Laptop seems to booth up but screen is black.Can even hear the sound of windows opening.And hard disk is reading.Noticed over heating.Might be a dead fan.Any advice or opinion will be appreciated.thanks in advance...
 
inverter

just want to ask if you have guide or manual on disassembling and assembling acer4535G. Had a black screen problem, tried external monitor.Laptop seems to booth up but screen is black.Can even hear the sound of windows opening.And hard disk is reading.Noticed over heating.Might be a dead fan.Any advice or opinion will be appreciated.thanks in advance...

maybe inverter problem which powers the backlight lamp. or dead gpu :(
 
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try external monitor if it works then change the inverter by taking of the front bezel on your screen and changing the inverter u cant miss it.
 
i tried external monitor and still it wont show anything,do you have any guide on dismantling 4535G? i already took off all the screws at the back and im having hard time lifting the front bezel on top of the keyboard and under the monitor.Its the bezel where the power switch is located.Hope you can give me tips on disassembling acer4535G.
 
Take off the 4 pads on the corners of the screen and pop the front bezel off be gentle and theres screws underneath u need to take out then pop the power key bezel off. Get bk to me and or i can walk throught a solution.fixed this issue before can be a pain
 
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