"A. Caspis" wrote in message
...
Hi

I have a 3 year old laptop which has suddenly developed the infamous
spontaneous abrupt shutdown syndrome. This is usually attributed to
overheating caused by dirty fans, but I am not convinced.

- I have tested various combinations of CPU speed settings, workloads,
power-management modes, AC vs batery, ambient temperature, etc.
- Shutdowns happen in the BIOS too, so it cannot be a software issue.
- I have enabled self-tests in the BIOS and used memtest86+.
- I have fully disassembled the laptop and reseated every connector.
- I have removed all non-essential modules and peripherals: bluetooth,
wifi, modem, keyboard, LCD panel (running on VGA with a USB keyboard).
- I have cleaned the copper air ducts and operated the laptop with
external fans blowing on all large chips.

Before I call it quits I want to try one more thing: reflow the PCBs.

The idea is not to melt everything, but only to reconnect any shaky pad
and destroy possible tin whiskers (this is an early lead-free design).

Recommendations regarding prerequisites, choice of air gun vs oven,
and safe temperature cycles for this particular purpose would be
appreciated




(I have zero experience with reflow soldering).

AC


IMHO that means you will need to practice and destroy a lot of motherboards
before you start getting things right. This really isn't the kind of thing
you should be trying at home unless you have a lot of money to spend on the
right equipment..


Try googling "reflowing BGA's". You will find some claims of success here,
though probably not many admissions that the fix only lasted a few days.
Mostly you will get total failures, I did. I would guess that the ratio of
reported sucesses to reported failures is quite large



Good luck.



Gareth.