On 19/12/11 14:43, Srdjan Todorovic wrote:
Hi all,
I'm looking at my mum's Acer Aspire 5520 laptop with Kubuntu installed that seems to have strange shutdown problems.
I can power the laptop on, but at random times (where t is generally< 2 minutes, sometimes up to 10mins, sometimes as little as 5sec) the laptop will power down completely with no user intervention. I've seen this happen while in the Grub boot menu, while Linux KDM login screen is displayed, while it's booting Linux, while it's running memtest and even while in the BIOS setup screens. This happens on the battery only, mains only and on battery and mains power combinations.
Does gentle flexing of the case make the problem come and go.
Googling about it does seem this model has the nvidia chipset with the classic RoHS Solder vs BGA chip mounting problems.
Oven/Hot Air Gun tricks will only effect a temporary solution I am afraid. A proper repair would require BGA reballing and that requires a reasonable amount of skill and equipment.
You can check it isn't thermal and at least eliminate that..The fins on laptops can look quite clear but still be well clogged up in the actual fan housing. Remove the HSF assembly..remove the fan assembly from the heatsink and look at where the fan blower meets the fins. Then reassemble with new thermal paste.
Beyond that it's going to be a replacement mainboard or find someone that can properly reflow BGA.