While it sounds like a motherboard failure ALWAYS try the cheapest thing it could be.
A new CMOS battery. It's a shame but I've run into folk that will not risk a dollar to see if it's that. I'm not telling you it's that but the next part it could be is more than what this laptop sells for.
Hi , this is my first post here, and i would like some help with my laptop ...
A few days ago, my laptop statred shutting off unexpectedly, at first i thought it was a heat problem , so i opened it apart and cleaned the fans and the heat sink , changed the thermal paste , and still nothing , the same problem remains, after a night , it worked for about 5 hours then suddenly shut off again , when i press the power button , the leds shined a bit then shut off again , and i say shut off not shut down , like it would be a current cut (or at first i thought a heat related shutting in order to protect the cpu )
I tried changing the power brick, with and without the battery, i took apart the hdd and booted of a ubuntu usb stick, still nothing , i changed the ram , took the cmos cell out then put it back , i wiggeled the power jack (there were no wiggle what so ever , well fixed )
Today it booted so i installed hwmonitor , all the values were in order (cpu voltage, fans speed, cpu temperature, hdd s.m.a.r.t ...)
So i took a deeper dive and i measured the voltage ; a steady 19.4v ....
In layman terms:
Sudden shut off even when idle , no moving parts whatsoever
Sometimes it runs for hours , other times it wouldn't even make it to 3 seconds
With or without the hdd
Changed the ram
Reset the cmos
Updated my bios
Cleaned the motherboard
Applied thermal paste
Two different power bricks
Internal and external monitors tested
It seemes tottally random to me ....
Any help would be very much appreciated
Acer aspire 5349 , 4 ram, windows 7 home premium, intel celeron