The problem is maybe the NVIDIA-Card:
Graphics:
Device-1: NVIDIA G98M [GeForce 9300M GS] vendor: Sony driver: nouveau
v: kernel arch: Tesla pcie: speed: 2.5 GT/s lanes: 16 ports: active: LVDS-1
empty: VGA-1 bus-ID: 01:00.0 chip-ID: 10de:06e9 class-ID: 0300
temp: 50.0 C
Device-2: Ricoh Sony Visual Communication Camera Integrated Webcam
type: USB driver: uvcvideo bus-ID: 1-2:2 chip-ID: 05ca:183f class-ID: 0e02
Display: server: X.Org v: 1.22.1.9 with: Xwayland v: 22.1.9
compositor: kwin_wayland driver: X: loaded: modesetting unloaded: fbdev,vesa
dri: nouveau gpu: nouveau display-ID: :1 screens: 1
Screen-1: 0 s-res: 1280x800 s-dpi: 96 s-size: 339x212mm (13.35x8.35")
s-diag: 400mm (15.74")
Monitor-1: LVDS-1 mapped: XWAYLAND0 res: 1280x800 hz: 60 size: N/A modes:
max: 1280x800 min: 640x350
Notebook runs some minutes, then screen freeze, ssh login is possible, but no restart or poweroff, only with the powerbutton.