Power on, no display

[cjt1024]

OMEN by HP Obelisk Desktop 875-0024

Product number:4NM66AA

Working perfectly fine for a few years. 
Recently added 16GB RAM for a total of 32GB and it took it no problem.

The issue I’m having now is the PC is booting up, but there is no display.
I’ve tried removing the RAM sticks and determining if they were bad. I wasn’t able to conclusively tell if they were, doesn’t seem like they are though. 

I’ve removed and replaced the graphics card as well as reseated the CPU. 
I’ve also upgraded the power supply to an EVGA 750W because I was hoping that the old 500W power supply was the culprit, but it doesn’t seem to be.

The only thing I’ve been able to get is when I’ve removed the CMOS battery and replaced it and once I turned on the computer I get 8 long beeps. That should be able to tell me what is wrong with it, but I can’t find anywhere what the 8 beeps mean. Closest thing I found was it meant something was wrong with the video memory, which I assume is the RAM, but like I said previously, I was unable to determine if those were the actual issue. However, when I get the 8 beeps, if I turn off the power, remove and replace the RAM, and turn the power back on, I don’t get the 8 beeps again. I only get the beeps after I’ve removed the CMOS battery.

Does anyone know what the 8 beeps mean? Or have a possible solution I haven’t tried yet?

Any help is appreciated. Thanks.

[itsmyname]

@cjt1024 -- Closest thing I found was it meant something was wrong with the video memory, which I assume is the RAM ...

Sorry, but "video RAM" is either RAM mounted on the video-card, or some of RAM (on the memory-sticks) that has been "borrowed" to be used by the video-card.

About the only component you have not replaced is the motherboard.  That would be an expensive part to purchase.