On 14 Jan, 10:20, "A. Caspis" wrote:
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

If it's one of the early model Thinkpads, they're notorious for
inductors dropping off, sometimes completely. Many people report
effecting a cure by resoldering just these and anything else which has
a large enough pad to do safely with your smallest soldering iron tip.

Google for a newsgroup or forum specialising in your particular model
and see what people there advise.

Chris