Thinkpad thermal paste replacement
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I live in a refurbished Thinkpad household.  I use an X220 as my
"daily driver" (lately it's sometimes been more like a "weekly
driver", but whatever), while my wife has an X230.  The X230 has
been struggling against pretty severe overheating issues for a long
time now.  It doesn't get hot enough to cross any alarm thresholds,
triggering a shutdown or anything like that, but it routinely
gets way too hot to comfortably use on a lap.  So, I finally
took advantage of recent holiday downtime to replace the thermal
paste on both CPUs and clean the fans out with compressed air.
This was by far the most substantial laptop maintenance work
I've done.  Back in the Good Old Days (TM) of IDE and ISA and PCI,
when RAM capacity and CPU clocks were strictly Megaunit affairs,
I knew pretty well what I was doing when it came to PC internals,
and my teenage bedroom often resembled one of those iconic scenes
from Serial Experiments: Lain, but it's been a looong time and I'm
well and truly out of the loop, hardware-wise.  I didn't become a
laptop user until quite late in life, and so I've just never done
anything other than replace hard disks or RAM.

The X220 wasn't really having temperature problems of its own.
But my wife is dependent on her X230 for freelance working from
home, so I was really concerned about messing anything up while
monkeying around deep inside.  In contrast, my employer provides
me with a work computer, so it's not a huge problem if my X220 is
out of order for a little while (although I'd be quite upset if I
managed to destroy it completely - this is the machine that both
Circumlunar Space and Gemini were born on!).  Therefore I figured
I'd re-paste both machines, and do the X220 first as a kind of
"learning experience", proceeding to the X230 if and only if the
first effort went smoothly enough that I felt confident of success.

This turned out to be precisely the right course of action, because
in fact I did mange (to my surprise!) to do some irreparable damage
to the X220, and thereby acquired practical knowledge which allowed
me to do a flawless job on the X230.  Also surprisingly, it wasn't
the actual thermal paste application part where I had problems.
That went smoothly on both machines and both now have significantly
reduced running temperatures, so the big picture is a success.
Instead, I powered the X220 up to find everything working just fine
except the WiFi card.  This is a small MiniPCI Express card which
slots into a socket on the motherboard and is then screwed down to
the bottom of the laptop case.  Because of that last detail, it's
necessary to remove the WiFi card in order to be able to remove
the motherboard, which is necessary because the heatsink is on the
underside and otherwise inaccessible.  At first I just figured I
must not have reseated the WiFi card correctly when putting things
back together, so I took it out again, wiped the contacts clean
with isopropyl alcohol, puffed some air into the slot, re-inserted
the card and booted up again, but still no dice.  So I went back
in and third time and took a much closer look, and that was when
I was astonished to find what I'd done.

If you have the laptop sitting flat and upright, you cannot actually
see the MiniPCI Express slot that the WiFi card goes into, as it is
on the underside of the motherboard.  Despite this you can insert
and remove the card while the motherboard is in place and laptop
is upright, due to the shape of the board (the slot is right up
against an edge).  The *correct* thing to do is to turn the laptop
on its side (if you move the screen so it's at about a 90 degree
angle to keyboard, then the whole thing will stand up very stably
on its side).  If you do this then you can clearly see the slot
on the underside and it's very easy to gently and precisely insert
the WiFi card exactly where it is supposed to go.  What you *don't*
want to do is just keep the laptop sitting flat and upright and try
to insert the card blindly, figuring "hey, it's pretty clear where
it's supposed to go, there's not enough *room* to be off by more
than a centimetre, so if you just keep poking around with subtle
shifts of angle it's sure to pop right in before long...".

Indeed, my card *did* pop right in eventually, but the
none-to-careful technique meant that first I managed to (and I
know it sounds crazy that this could be possible without resorting
to obviously irresponsible levels of force, but I swear it wasn't
difficult) scrape, for want of a better word, some of the slot's
thin metal contacts free from its plastic "mouth", so that the
eventual insertion crushed them down into the base of the slot.
We are talking about strips of copper less than a millimetre wide
and far less than that thick.  I destroyed three adjacent contacts
this way.  As far as I can tell, nothing has actually physically
broken, such that with really high magnification, good light and
some kind of very fine manipulator tool connected to some kind of
force-reducing control interface (you know, like what Automatic Jack
has in Burning Chrome), it might be possible to straighten those
contacts out and push them back into place and have things work
(then again, maybe the crushing has shorted some neighbouring pins
together and that's damaged a controller attached to the slot, who
knows?).  But, it's not remotely worth trying something so fiddly
and frustrating; as a legacy of the early Raspberry Pi models,
we live in a world awash with very small and very cheap USB WiFi
adaptors with good Linux driver support, so I was very easily able
to source a literal plug and play solution and now there's no long
term consequences associated with this little stuff up.  Still,
it certainly doesn't feel good to have done *any* kind of lasting
functional damage to a working machine.

Nevertheless, I'm really glad that I tried doing this and was for
the most part successful.  Getting to the heatsinks of these machines
really requires a *complete* tear down.  You are left with the bottom
shell of the laptop completely empty.  As such, I now feel very
confident about doing *any* future maintenance or repairs on either
of these machines, and that's a good, empowering feeling to have.
Older model ThinkPads have a strong reputation for being very easy
to work on.  I can't really say with conviction that this is true,
simply because I've never done a remotely comparable procedure on
any other model of laptop for comparison, but I certainly can't
imagine a laptop being considerably *easier* to work on.  I was able
to use just a single screwdriver for the whole procedure.  All of
the screws accessible from the outside of the laptop are black,
and they are all the same size.  All of the screws accessible from
the inside of the laptop are silver, and they are all the same size.
You don't need to touch any internal silver screws at all to replace
the keyboard or the TouchPad (which can be replaced separately).
Aah, actually, "just a single screwdriver" isn't true, the X220
(but not the X230) required a pair of needle-nosed pliers to remove
the hex screws on either side of the VGA port.  Absolutely no exotic
tools are needed, let's put it that way.  Aside from the VGA port
screws, the two models tear down identically to one another, so
if you're comfortable with one you can do the other, no problem.
Very practical machines, all things considered.