Laptop not starting BIOS

Hi All,

    First of all, I hope I posted this in the correct category.

    A few days ago, I woke up, and decided to check my email, as I always do. The laptop (a Dell Inspiron 5523) had been fully shutdown previously. When I pressed the power button, the power button lit up, I heard the hard drive click on as the disk usage LED flashed, and then a half second later, the HDD clicked again as the disk usage light flashed. Throughout, the power button stayed lit, but the screen had stayed completely black.

I pressed the power button to shut it down, then pressed it again to start it up. The same thing happened. I tried it a few more times, and finally, it ran BIOS. However, and before it started the Windows Boot Manager (the laptop is dual-boot, Win 8 and Win 10 Tech Preview), it displayed a BSoD with the error "PAGE_FAULT_IN_NON_PAGE_AREA (iaStorAV.sys)". I restarted it, and it went back to the original symptom: no BIOS. Finally, after many tries, to no avail, it would not display BIOS. I pulled the ram, and with no ram, it beeped the proper POST code for no ram. This signifies that it is performing POST.

I added the ram back in, and when I got to work, my friend and I tried the old "Atari Twist" (ie. hold either end, and twist it back and forth. Miraculously, it loaded BIOS. I entered the low-level diagnostic utility that is present in it's BIOS, and it checked everything, and decided that everything it was capable of checking worked.

Finally, I pulled the HDD to recover my data (a real pain on this laptop - you have to take out almost everything except for the motherboard just to access the HDD), and, after plugging it into a USB SATA dock, decided that it works perfectly (hey! an external HDD!). Then, I started taking out, one at a time, various components, and trying to start without them  I have removed and tested, to date, the following items from the motherboard:

    Ram

    mSATA card

    Optical Drive

    Coin Cell 3V Battery

I have not managed to remove the wireless card, because I managed to strip the screw that attaches it to the motherboard.

So, does anyone have any ideas? Is my motherboard toast?