Intermittent shutdown: overheat or keyboard short?
I have a late 2010 MBA which occasionally pops up a dialog box asking "if I want to shut down" then turns off by itself.. I can not interrupt the shutdown sequence. The laptop was bought used, although in great cosmetical shape and with a 256 Samsung SSD. On software side it's running Mountain Lion with all software and firmware updates installed.
Now I know enough to conclude this is some intermittent electrical issue, probably a power button short. What is interesting, the shutdown dialog doesn't appear if I hold the Fn key pressed. Now I literally need to put something heavy on it all the time because the frequency of this issue has increased to many times per minute. Note there has been a similar issue on the stackexchange forum: http://apple.stackexchange.com/questions... and top case replacement was suggested.
I took the laptop to a private person who specialises on Apple gear here in Vienna and he did some diagnostics, tried running with disconnected internal battery etc.
What we noticed with case open is that the cpu is getting really hot. He concluded it is most certainly not a keyboard, but thermal issue and recommended renewing thermal paste. However, running temperature monitor I see that idle cpu is 55C degree hot, with youtube paused about 77C degrees, under load 85-90C degrees.. which is pretty hot, but not extreme so I am not convinced.
If replacing the grease doesn't cure the problem I'm not sure this person will be able to help me, so I'd rather find someone who has more extensive experience before paying $$. I'm gonna run some kind of memtest overnight, but I don't really expect it to find something. Yes, I got a BSOD a few times, but this started happening after enabling FileVault encryption and I attributed that to incorrect shutdown.
1. What do you think is the problem? Shall I attempt to get the keyboard cleaned or replace thermal grease? I'm not 100% sure about either option. The 0 and [ keys have been sticky when I got it, the power key however seems perfectly clean.
2. How difficult is it to replace thermal grease on MBA 2010? I did that on Lenovo laptops a few times but have no tools for Apple. Shall I pay 50 EUR for the job or attempt to do it myself?
3. I'm searching somebody specialising in MacBook repairs ideally from Germany or Austria. I know there is remacberlin on ifixit, but I have no idea how to contact him..