Pi3 won't display on HDMI-VGA; first boot

[SuperSquooch]

My Pi3 is booted for the first time with a brand new SD card loaded with NOOBS. It has booted successfully, as evidenced by the ethernet port LEDs flashing with a connection. The HDMI out is connected to an active (and working) HDMI-VGA adapter, which is connected to a VGA monitor. However, the monitor doesn't recognize this fact, and it says "cable not connected".

Okay, so the monitor doesn't recognize the Pi3. Fine. BUT, I need to see what the Pi3 is doing so that I can shut it down without screwing up the SD card. So, what other ways can I display the Pi3's output WITHOUT shutting it off?

[DougieLawson]

If the green LED stops winking you're going to be mostly OK just pulling the power. I pull power all the time.

Don't worry if you trash the SDCard since the most likely final outcome will be that you need to reformat and write NOOBS 1.9.2 on it (or use Win32DiskImager to write Raspbian 2016-05-27 on it) to over come your boot failure.

Read: viewtopic.php?f=28&t=58151 to understand your options.