T4X 14.1 vs T4X 15.1 lower cases

[tim S]

I've just completed a major transformation of a 14.1" T42 but
now there are some heat issues. Nothing too major but the fan
is working a little more than I was used to and the underside
is definately hotter than it was before.
I noticed that the 15.1" lower casing has more venting slots
than the 14.1" model, which I find a little odd since the larger
housing should have better cooling simply because of it's size.

Is there a 14.1" lower case with more venting slots, or are they
all the same?

Judging by the photos on eBay they all look the same but not
all were represented. According to the HHM there are an astounding
12 versions of the 14.1" lower case and that doesn't even include
about 5 more made for the Korean market!

Tim S

[poshgeordie]

Hi Tim

When you say it's hotter than before, is this based on actual before and after temperatures, or that it just feels hotter underneath?
It could be worth installing tpfancontrol and post some typical temperature readings which we can then comment upon.

Also check the following:

1. When you did the changeover, if you removed the fan you MUST renew the heatsink compount. A lot of people suggest using Arctic Silver but anything will do for general T4x's.
You first need to clean off the old stuff from the heatsink and CPU. Then apply the thinniest amount you can to the CPU - the compound is there just to fill in metal to metal imperfections.

2. Did you clean out the fan? I always find there's loads of dust there so regardless of what repairs we do, we always clean out the fan and heatsink fins.

3. Is the fan properly seated on the CPU? It's possible to get it so that it doesn't quite sit properly on the CPU.

[tim S]

Hi Nick.
Heat, at least laptop heat, is a very subjective thing. I just felt that after my upgrades the fan was working
more, and the underside was hotter than it was before.
Before.....was the same CPU (1.8Mhz) but a 32MB GPU. Now I have a 64MB GPU which was part of a board
upgrade. I had a long fan (eBay) on the 32MB GPU, I guess to hold it in place more than anything else! The replacement board also came with a long fan and I noticed that the pipe over the GPU was thicker and straight, while the 'original'
fan had a slightly thinner pipe that was curved. Obviously there was various attempts to combat heat and fan
piping was one of them. I'll check tonight to make sure the heatsink is correctly positioned over the CPU but I
did apply 'arctic' sliver after a thorough cleaning to remove the old paste. I left the strange stuff on the heatsink
over the GPU but it isn't quite centralized, there's a good 1/8" of GPU uncovered, so I'll work on getting
that fixed as well.
I noticed that certain T43 fans have a heatsink that covers the northbridge as well as the GPU, maybe I'll give one
of those a shot.

Tim S

[poshgeordie]

As you say it's very subjective, however you do have a more powerful GPU which will run hotter.

Re the black goo on the top of it, you'll need to make sure that none of it is sticking up such that it's preventing that part of the heatsink making good contact with the top of the chip.
An alcohol-based cleaner (eg meths) will easily dissolve it and the cleaner the top of the GPU is, the better the heat transfer.

Also it's not a problem having the edge of the GPU uncovered so long as the middle part where the Radeon chip metal die (under the GPU heatsink "cover") is covered by the main heatsink.
The long heatsinks are meant to have a pink material heat conducting pad underneath in the GPU area.

The heatsink with the northbridge heatsink is for T43's with the Intel GPU and I don't see that using one of those will improve things; if I remember rightly it's slightly smaller over the GPU so I'd stick to the heatsink that's designed for the job.

There's been a lot written in the forums about temperatures and it's worth doing a search to find what others have experienced and any good mods etc.

[tim S]

Well I got the fan out of the laptop and really gave it a good going over. I sprayed the heck out of it
with WD40 dried it off and used a drop or two of fine household oil. Now it rotates more freely
and more quietly than before.
I see the heatsink is actually smaller than the GPU so there was no way for the heatsink to completely
cover it.
I might still go for theT43 fan because the northbridge chip generates quite a bit of heat. Of course it
may become a case of deminishing returnes since the fan will have to work harder in order to cool more!

Tim S