Well, after troubleshooting and scouring the internet for definable solutions (of which there aren't many) I figure it's time to ask for help before I give up.
My PC was running fine for a good three years now but several weeks ago I noticed its boot times were getting a lot longer. Then, it took several minutes just to reach the post, or, after restarting, it wouldn't even get to the post screen.
According to the manual doctor debug defined the 4f as DEXE IPL is started, along with some others which just sounded like its routine boot process. Problem is, it would get trapped in this state. Some have suggested all sorts of things: clear CMOS, take out the battery, replace battery, BIOS chip is corrupted, unseat things, etc.
It's difficult to say what the culprit is, and I tried many routine things to get it working, like clearing CMOS.
It's also possible in my insistence to fix the issue I might've made it worse - I took out and reseated the heatsink/cpu, and the gpu, and the power supply, which didn't solve the issue. Now, after the system stays in its "loop" long enough, I also see the red LED code "d6", which according to the manual "no output device found."
After that, I've also seen 67,which means CPU DXE initialization (it will get stuck here). So, now I'm concerned I may have damaged the CPU once I reseated it (will have to check again).
At this point I feel like I need to replace a component, but I can't even tell what. If I busted the CPU and get a new one, what happens if the 4f error returns? I've spent hours on it today and feeling next to hopeless - I can't even get to my files now and can't work. So, any advice is greatly appreciated.