08-03-2016 01:11 PM - edited 08-03-2016 01:32 PM
I've been using this L412, #4403, for a few years, and quite satisfied with it.
Sorry for the long post, I believe the chain of events are relevant to the issue.
A few days ago the fan died. I cleaned the laptop less than half a year ago so probably not dust issue. I dual-boot Windows 7 and Linux Mint Qiana and it wouldn't work on either of them, so probably not OS issue. BIOS doesn't have any fan info.
Replaced it with a new fan, correct model, everything according to the manual and proper CPU fan replacement practices.
After assembly everything was working as usual. Next day everything was working as usual.
On its second day the fan didn't turn on when I turned the laptop on. At the same time, trackpad and trackpoint stopped working, volume control doesn't work, and the special Fn keys don't work.
The F1-F12 keys work. Insert, Delete, Home, End keys work. The Fn+Insert does a Screenshot as it should, but none of the other Fn special keys work.
All that happened at once, from the moment I booted up the laptop.
I checked the two OSs again. None of the above work on either of them. Doesn't work during boot-up sequence.
Found a way on Linux Mint to turn on the fan to full-power, but it's like that only after the OS reaches the desktop. Auto mode makes it turn 0 RPM, full-power makes it turn at about 435 RPM (very stable).
I assume it's not an OS issue because it stopped on both of them at the same time, and it doesn't work during boot-up sequence even though it used to.
I assume it's not a problem with the fan because I can force it to turn on.
Because the trackpad and trackpoint stopped working at the same time (even though they worked after assembly), and the special keys stopped working at the same time, I suspect a deeper problem.
Maybe motherboard? Maybe some controller?
How should I approach troubleshooting this issue?