M4600 freezes after being in service

Hello,

Because of the chirping noise I sent my m4600 to the support.

Now it's back and has more problems than before.

The first day it worked fine, but now it takes several minutes until it freezes completely. The HDD LED is permanently on. The coursor can be moved, but I'm not able to do anything.

My first idea was to install a backup that I made before I sent the notebook to the dell service. But the problem remains. One day it works fine, the next day it does not.
I reinstalled the backup a second time, same problem.

The other problem is that I'm not longer able to configure the time unitil it switches into standby mode. Now is fixed 30 minutes (15 minutes on battery). Windows says that the setting is currently not availible.

Does anybody have any idea??

My system:

M4600 i7
Firepro
FullHD (standard)
12GB Ram (original 4GB)
250GB Intel SSD (original 250GB HDD)

The Dell support told me to remove the addidional RAM, and to install their revovery.
Removing the additional RAM did not help (both problems). Installing their recovery I did not try so far, because I don't know how to access the recovery partition.
I also tried to use the HDD again. The stand-by issue is still there. It did not freeze so far, but I build in the HDD yesterday, so it can still happen.

Any ideas?

Cheers,
Christian