cleaning my SL500, now 105°C

[hannes7]

hi all,

i cleaned my SL500 yesterday.
for this i opened the cover on the backside. got the heatpipes with the fan out. cleaned everything, put some new heat transfer paste on the chips and got the cover back on.

i started the SL500 and after 45 seconds the fan rotates on fullspeed.
downloaded Speedfan and saw the following:
GPU: 50-60°C
HDD: 30-35°C
temp1: 105°C
Core0: 35-55°C
Core1: 35-55°C

the problem is not only the fullspeed of the fan, the SL500 overheats and shuts immediality down.

So, where is the temp-sensor named "temp1" located??
which component is behind it?!

did anyone got the same problem or have any suggestion to fix the problem?

Thanks!
Hannes