HP ProLiant DL180 G6, got stuck in the booting up screen, cannot get access to BIOS

[RavenC]

Today, I wanted to check the hard drives status in the BIOS on a HP ProLiant DL180 G6 server.
This post might be frustratingly long, so as my day.... (Please bear my spelling and grammatical mistakes... I am totally exhausted after this task, but still want to know the reason behind it...)

When I connect a monitor to the VDI port of the server, there's no signal. I need to press Ctrl+Alt+Del and wait for around 30-60 seconds to have something to show up. (see the attachment below).

After this screen, the monitor becomes no signal again. Normally, the server will give you choices to press either F9 or F10 to go to different screens. But this server somehow doesn't.

So, I thought maybe the F9 and F10 flash away so quickly that I can even see it. Therefore I pressed  Ctrl+Alt+Del again and waited for another 30-60 seconds to reboot it, then I repeatedly pressed F9 crazily fast. Yet, nothing happened. No signal right after the same screen.

Then I tried F10, failed;

then tried Enter, failed.

In the following 30 minutes, I tried almost everything from F1 to F12; none of them work.

Then, I thought maybe unpluging the power cord will do. In another 30 minutes, I tried uplugging and replugging the power and repeat the same process mentioned above, hitting all possible keystrokes. Still, no luck.

Up to this point, my boss is so pissed. it takes too long for me to do a simple task.

But I really have no idea what's going on here, the server doesn't behave normally as what I would expect. I spent another 1 hour to change keyboards, moniors, VDI cables and search for solution on the web. Yet, the problem still presist.

Could anyone please help me out? The same screen appears over and over again over the past 2 hours....