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~misfit~[_3_] ~misfit~[_3_] is offline
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Default reflowing BGA with a hot air gun?

Once upon a time on usenet Jeff Liebermann wrote:
On Thu, 08 Feb 2018 17:37:25 -0800, wrote:

Thanks for the advice Jeff. And the link. I did take this machine
apart once about 5 years ago to replace the hard drive. That all went
fine.


That's a start. However, to reflow the BGA chips on the motherboard,
you'll need to remove the motherboard from the plastic case. I take
photos as dive into the machine. Seems to impress (or panic) the
customer. For example:
http://www.learnbydestroying.com/jeffl/pics/repair/HP%20Envy%20m6%20clogged%20fan/slides/HP%20Envy%20m6%20A10%20CPU.html


I had to LOL at that. I have an HP Envy dv7 laptop that I don't use anymore
even though it's by far my most modern computer. Being an invalid with
chronic lower back pain vacuuming is one of the most crippling household
chores so it doesn't get done as often as I'd like.

The Envy has such a high air through-put that it doesn't take long to injest
enough dust to start causing problems. Also it's no IBM ThinkPad when it
comes to dis/assembly and has quite a few plastic tabs which won't handle
many cycles before breaking.

So I still use my ThinkPad T60 / 2GB RAM Win XP while my envy with i7 / full
HD display / 32GB SSD-accelerated 1TB HDD / 16GB RAM sits in a drawer. I
used it for a week or two but could tell that even in tat time and trying to
be careful of dust the airflow was reducing... This T60 pushes far less air
through and is simple to pull down once a year to clean the fan and fins.

I got the dv7 from a neighbour who offered it to me in return for data
recovery from it. (It got so hot that it wouldn't run for long, the RAM was
'cooked' and causing HDD corruption every time they tried to read from it
and it randomly shut down. I installed the new 16GB after I was happy there
was a good chance it would work again.) Maybe I'll get to use it when I
finally have to go into assisted living - if people still use laptops then.
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)

Your "unspecified model ASUS" remark made me laugh because
when I was typing out the original message I realized I didn't have
the model number on hand and knew at the time that I really should
have included it with my post. I always seem to get caught.


That's a catch phrase that I use quite often. An amazing number of
people ask questions without supplying much in the way of identifying
the device they're trying to repair. If they're stuck on something,
they will describe what they've done, but not what problem they're
trying to solve. After many years, I suspect the problem is chronic.
Here's my magic formula for getting mostly sane answers on forums and
newsgroups:
1. What problem are you trying to solve? No history or product
reviews, just the problem.
2. What have you done so far and where are you stuck? What happened?
3. What do you have to work with? Maker, model, version, numbers.

This won't work for a laptop, but I've been successfully reflowing HP
Jetdirect cards in a toaster oven. So far, 18 working boards out of
20:
http://www.learnbydestroying.com/jeffl/pics/repair/BGA%20reflow/index.html
Also about 15 assorted HP printer PC boards and a few game boards.
Protecting plastic parts, that are easily melted, is the main problem.
Aluminum foil shields do not work, so I have to remove the parts. Most
everything else that can survive PCB soldering, can survive the
toaster oven reflow. Unfortunately, there are too many plastic parts
on a laptop motherboard, so it's not going to work.