[ltp] T520 Wireless

Steven J. Owens linux-thinkpad@linux-thinkpad.org
Fri, 21 Sep 2012 18:07:11 +0000


     I replaced the fan on my t43p a few years back, which required
replacing the thermal paste.  I'm one of those guys with a "black
thumb" when it comes to hardware - if there's a way it can go wrong,
I'll find it.  Nevertheless, I found replacing the fan quite doable.
If I can do that, you can probably handle yours :-).

     The thinkpad hardware maintenance docs are pretty good, just
google on "t520 repair manual" and it's the first link that comes up,
a PDF.  Or grab it from here:


     The docs break things down - for example, to remove the fan (aka
FRU 1150 Thermal Module, page 83 of the manual but actually page 91 of
the PDF) the first thing it tells you is a list of the other FRUs you
have to do first (battery pack, DIMM slot cover, keyboard, keyboard
bezel assembly, speaker assembly).

     When you do the actual assembly,A trick I figured out years ago
is to get a piece of masking tape or two-sided tape and secure it
sticky-side up nearby.  Then place the screws onto it one at a time,
in order as I remove them.  The screws stick to the tape instead of
rolling around and getting disorganized.

On Fri, Sep 21, 2012 at 11:35:33AM -0300, Henrique de Moraes Holschuh wrote:
> On Fri, 21 Sep 2012, Richard Neill wrote:
> > 3. When swapping CPUs, be very gentle, don't bend the pins, replace
> > the thermal grease if necessary.
> It is almost always necessary.  And you need very good thermal compounds for
> this, so acquire them beforehand.  A safe bet is Arctic Silver 5, but there
> are many others that will also work just as well, or even better.

     You only need about a rice-grain-sized drop of the paste.  I did
a bunch of reading around and ended up using artic silver 5 as the
safe choice, based on advice from various people.  Also :-), partly
because the first time I replaced a fan, a friend had a tube of arctic
silver 5 lying around and loaned it to me.  Then I did it a second
time and bought my own tiny tube of arctic silver 5, now sitting in my
desk and waiting for the opportunity to be loaned to somebody else.

     Something interesting that wasn't predicted by the docs or
anybody's tips is that, when I lifted the t43p fan out, between the
fan and the CPU there was a large blob of some rubbery pink goo.
Waaaay too much for it to be an appropriate amount of thermal paste.
I was honestly worried that the CPU heat had caused something to melt.

     A little googling turns up only a few mentions of this stuff.
IIRC at the time I asked here and it was suggested to just scrape it
away (carefully, with a dull butter knife or a credit card, to avoid
scratching the CPU) and put a drop of arctic silver on it.  It seems
to have worked because that t43p is still working fine.

> They are all expensive, but you will need so little, you can just buy the
> smaller container you can find.  Whatever you do, get something that does
> not become too liquid at any moment, that can handle large dynamic thermal
> cycles (laptops go from cold to hot to cold again several times a day) and
> don't even _consider_ getting one that reacts with metals or conducts
> eletricity.
> > 4. Either remove the sticky screw covers very carefully with a thin
> > flat screwdriver (so you keep them sticky), or buy spares for $5 on
> > eBay.
> If you're going to buy the covers, also get a thinkpad screws set for your
> model in eBay.  Teflon-coated screws really are not meant to be reused
> several times, they lose the coating.

     Yeah, I definitely noticed that problem.  Also, I'm not sure if
this was something I did wrong or just normal wear and attrition, but
I found that the screw holes stripped very easily.  I might have
overtightened them, but if so then I found it *very* easy to
overtighten them.

     I got a replacement pack of thinkpad screws from thinkpad
warranty service when dealing with a different repair on a different
machine.  They were happy to just throw a pack of screws in the
package.  If you have another machine that's still under warranty,
give them a call and see if they'll send you a packet.

Steven J. Owens
puff@darksleep.com / (412) 401-8060 cell 
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