Suspend to RAM is not working

I have been using the board qc5000 ITX / PH for 1.5 years.
As OS I use windows 7. As memory I use 8 GB DDR and no additional hardware like a graphic card.
Until 1 month ago the system worked perfectly. I used Suspend to RAM for a faster restart and it worked fine.
But now the suspend to RAM is no longer working.
It seems like the data will be stored on the HDD instead of the RAM and the Power LED will not flash.
A wake up via network or usb doesn't work any longer.
A reset of the BIOS and a reinstallation of windows 7 did not help.
What could be the problem?

Obi25 wrote: I have been using the board qc5000 ITX / PH for 1.5 years. As OS I use windows 7. As memory I use 8 GB DDR and no additional hardware like a graphic card. Until 1 month ago the system worked perfectly. I used Suspend to RAM for a faster restart and it worked fine. But now the suspend to RAM is no longer working. It seems like the data will be stored on the HDD instead of the RAM and the Power LED will not flash. A wake up via network or usb doesn't work any longer. A reset of the BIOS and a reinstallation of windows 7 did not help. What could be the problem?

Have you installed any driver updates yourself? Before or after you installed Windows 7 again?

Have you compared the driver version numbers in your Windows installation with the versions on your board's Windows 7 download page? Or do you just use the default Windows 7 drivers, and any installed by Windows update?

The symptoms you have only make sense if a Windows 7 update installed a different driver for the Realtek network chip, and the WOL settings in Device Manager were changed. Are you sure the WOL setting in the BIOS is still set correctly, if it even has such a setting?

If the Suspend to RAM (S3 Sleep) now seems to be Windows Hibernate, writing to the disk (which normally still writes to DRAM anyway), that may indicate that your memory usage is so large in Windows, it can't be saved to DRAM memory. Or Hibernate has been enabled in Windows 7, by an update or something else. Have you checked your Windows Power Plan or Power Button options, for the S3 Sleep or Hibernate settings?