Hi edagro,
Ensure the Auto Power on is Enabled:
- Restart the computer and press F2 when you get to the Dell screen.
- Use the arrow keys to find the "Power Management Setup and hit Enter.
- Scroll to "Automatic Power On" and Enable it.
- Now Set the Auto Power on Date and Auto Power On time.
- Tap F10 to Save Changes.
- Now restart the computer.
Turn it off each night. It will boot itself up at the set time.
Awaiting your response!