Starting a computer with Audio Visual cables?

[Sir Dude]

Okay, here's the situation. I'm building a sleeper PC and it's gonna be the first PC I've ever built. I don't have a lot of money, so I need to make sure that the parts I buy are what I want and basically everything is right the first time around. My biggest issue was getting the old 98's power button to work on newer hardware. I spent a lot of time fussing and worrying and asking and researching it, but eventually I opened up an old Windows 7 I had lying around, figured out where the power button is plugged into, and wouldn't you know it the 98 cord is too small and won't fit.

However.

The 98 case I'm using has red, white, and yellow Audio/Visual cables (I don't know for sure if AV is the right abbreviation for that but I'm using it anyway) ports built into the case with a cord that runs down to the motherboard and is plugged in. And that cord fits in the power button port on the 7 motherboard. I kept the PC plugged in (I know, great idea) and I tried different positions and rotations. I also had nothing plugged into the AV ports. Surprisingly enough, the PC was able to power on with nothing plugged into the AV ports, albeit it would only kick on for a second, then power back down. I found one spot where it would loop that process (boot looping, I think?). I got nothing overall so then I tried plugging in AV cords as well and with some funkiness I can turn the PC on and off with AV cables.

Now, I don't know much of anything about computer hardware, especially the intricacy of circuit boards, and I'm not gonna go start buying very expensive parts just because I got good results with 1 old computer. The most I know is that this Windows 7 has 10 pins arranged in 2x5 and the AV ports have 6 pins arranged in 2x3, and I have it plugged into the far left side of the pins. The only markings are "F_Panel" "MFG" labeled on the right side of the pins. I tried looking at pictures of motherboards to see if there's something similar to the 10 pins but I don't know and I couldn't identify anything. The AV ports that I'm using came from a Compaq Presario 4814 Windows 98 PC. The test computer I'm using is a Windows 7 HP Pavillion, and anything else that can identify it (like model number) are beyond me unless somebody tells me where to look. I'm wondering if I can replicate this on other motherboards, especially new and modern ones. I don't have any on hand and I don't know anybody who has one I can mess with. I would really prefer this method works first before I fry something very expensive. Any and all help is appreciated, and thanks in advance.