Workarounds for no monitor output

[RonB]

Several years ago, I retired my work desktop to serve streaming video on my TV. It has worked fine until 2 days ago. I have Windows 10 Pro with all updates (except possibly ones from the last 2 days). Now I get no monitor output at all. I can't even see the motherboard startup screen. Oddly, I think, the TV, as well as a standard PC monitor I tried, doesn't say there's no video input; it's just black.

My graphics card is a GeForce GT 220. The motherboard is a Gigabyte GA-B75M-D3V. I don't know the CPU and want to avoid having to take the fan off and try to get it clean and reseated again.

My questions:

1. If I mount the Windows 10 share on my Linux machine (the share is all of my files, etc.) can I find out what the CPU is. This would tell me whether the CPU has built in graphics. I tried HDMI and DVI on the graphics card with no luck. I tried HDMI and DVI on the motherboard outputs with no luck. Since I can't see the BIOS settings I can't change it to on-board graphics even if they exist, I guess.
2. Can I find the WORKGROUP password on the machine? That would make it easier to access files. It seems to exist in plain text but I don't know where.
3. Should I expect SSH to work with this machine. It's up to date and I understood that SSH was enabled by default. I tried it; didn't work.
4. Is there any way to boot to safe mode. I didn't make the change to re-enable F8.

Any suggestions or help on how to approach this would be very much appreciated. I'm stumped.