Hello. I did bunches of searching, but it seems like this is an issue with a lot of different symptom sets, and most seem to have slightly different solutions, so I decided it'd be better to make a new thread and try to compile recommendations for this particular case.
The machine is an ASUS ROG g751jt. I was running BIOS version 208 without experiencing this issue, and decided to update to the most recent in order to try to fix of the "machine stops while in sleep mode" issue. Flashing the BIOS went without a hitch, no errors or hangs or anything in particular. But, after the flash, on the reboot, the machine goes into a cycle of turning on the monitor (nothing displayed, no splash screen, just a black-but-active screen), holding for a couple of seconds, then shutting off and repeating the process until I go into the BIOS menu with F2. After I exit the BIOS menu, without making any changes, everything continues normally and I'm able to continue the boot process. This happens every time I restart, which is even more common than it used to be because the machine now shuts itself off *every* time I enter sleep mode, not just sometimes.
I have tried reflashing the same version with WinFlash, as well as using 210, and have the same symptoms. I plan to try 208 again, but it doesn't really seem like this is an issue with the BIOS itself--some of the threads I pulled up seem to indicate that this is hardware-related, although it's strange to me that an issue of that sort could be triggered by flashing the BIOS. Does anyone have any authoritative recommendations for this? Am I looking at wasting a few hours on a teardown to try to reseat everything (and hopefully not brick the machine in some way in the process), or is there an easier solution I'm overlooking? If I am staring that down, could anyone give me some information on *why* that would work, like what the root cause is that I'm fixing by poking around with the machine's innards?
ETA: If it matters, I flashed the BIOS from my main partition ("C:"), rather than from a USB or similar.