so, i was looking at the temperature of my new used laptop: a dell e6530 with a very fast i7-3740QM processor.

i boldly decide to put new thermal paste, looking for a cooler temperature. bold because i know on this model, you don't have to totally take it apart like many today.

no problem removing the cooling unit, seeing the CPU and GPU, cleaning off the old paste and putting new.

then i put it back together and start it up: no boot, not even into BIOS.

stunned, i soon go to my desktop and browse for solutions.

'move the RAM pieces around for a while'.
'unplug everything and the battery, then push the power button a few times'.
're-do the thermal paste, it probably got hot'.
'you touched something static and your motherboard is dead'.

i do what i can of the above; nothing works.

i go browse again, set to call a repairman. then i see another comment, suggesting i should unplug the little CMOS battery and plug it in again. i am thinking 'no way, i was just putting some new thermal paste, i didn't even touch anything!' 10 minutes later i decide to take that one last shot.

it worked.