Debian Configuration :: Screen Goes Blank During Boot On 8.1

I have this machine (motherboard ITX Jetaway NF94-270-LF based on CPU Atom N270, full specs here) as a server for some time now (about 4 years). Debian 8.1 is installed on it.

Two days ago, after a power failure, the machine was not able to complete the boot process. I attached a keyboard and a monitor (on VGA port, the motherboard also as a DVI one, but I don't have a suitable monitor) to be able to see what's happening and interact with the machine. Unluckily, at a certain point during the booting sequence the screen goes blank and the monitor goes in standby mode; apart from that, the boot process continues in the background.

As far as I can recall, this behaviour existed for at least a couple of years (if not from the beginning) and the boot process was always completed successfully until two days ago.

The screen goes blank after the setup of the keyboard mapping. I tried everything to avoid the screen going blank: in the Grub menu I set the "vga" parameter, the "nomodeset" parameter, the grub_gfxmode parameter, I removed the "quiet" option, I removed the "load_video" line, I forced the BIOS to only use the VGA port for the video and so on, in order to disable or configure differently the video and the framebuffer. All these stuff had no effect at all: the screen keeps going blank at the same point during the boot process.

The only way I was able to use a fully booted system through keyboard and monitor was via the rescue mode of the Debian 8.1 netinst image. But that way, of course, I wasn't able to observe the normal boot process. So, I checked the boot parameters of the rescue mode and I found that the only usefull parameter was "vga", which I already used and was ineffective.