Had the same problem, solved with the following steps:
1) remove the battery
2) press power button
3) vacuum clean the ventilation window for about 1 min
Possibly the last step is the decisive one, since the air flow also cooled down the computer
1) remove the battery
2) press power button
3) vacuum clean the ventilation window for about 1 min
Possibly the last step is the decisive one, since the air flow also cooled down the computer