The MSI forums at https://forum-en.msi.com
may be able to help, and their instructions for flashing BIOSes sometime differ from those given by MSI. For one thing, the forums advise against updating the BIOS from anything but a USB flash drive.
Have you tried holding down the CTRL and HOME keys while turning on the power, until the motherboard beeps? That may bring up boot block mode, which tries to load a BIOS image file from a USB flash drive. MSI says the BIOS file has to be renamed AMIBOOT.ROM, but apparently that's wrong, and it needs the original name given to the file by MSI. I believe you need a plug-in video card because any video built into the motherboard won't work in this case, and the card may even have to be an ancient PCI card. Some people report that different USB ports have to be tried and that some USB flash drives don't work.
I had one MSI motheboard that was brought back to life with the boot block programming method, but with another motherboard it just kept asking for a certain BIOS image file, regardless of what the file name was or its contents. For that motherboard I had to resort to an SPI flash, where the BIOS image is transmitted directly into the 8-pin serial BIOS chip while the motherboard is turned off (not even a CPU or memory is needed). There are USB devices for doing SPI flashes, but I used the parallel printer port of an old computer and made a cable as described here: http://www.fccps.cz/download/adv/frr/spi/msi_spi.html
. The software is SPIPGM2, which has to be run from DOS, although a version called SPIPGMW will run from a DOS box inside Windows. With MSI motherboards no soldering is necessary for the cable because they have an 8-10 pin header, labelled JSPI1 that connects directly to the BIOS chip, and on your 770-C45 the header is located between the SATA connectors and the CMOS battery jumper. Notice that the cable from the parallel printer port has a resistor in series with each wire except the ground and +3.3V power wires. These are absolutely necessary because the parallel port uses +5V signals while the serial BIOS chip uses +3.3V signals. Apparently 150 ohm resistors don't always work, and it may be better to use around 240-270 ohms. I used 240 ohms simply because I had a bunch of them. Here's a YouTube video of someone e attempting the SPI flash:
BTW SPI flashing requires an image file of the BIOS, not a self-extracting file that's often now the only type they provide at their website. They do send out image files on request, but not always the right one.
I've experienced only 3 BIOS flash failures in my life, all with MSI motherboards. Coincidence? I've heard so many bad stories about MSI flash failures that I won't update a BIOS unless I first find 3 people who've done it successfully with my exact same model motherboard. Strangely, it seems that many people lie about successfully making such updates. OTOH MSI offered to flash the dead motherboard for free, despite it being long out of warranty, but required that I pay for shipping back to them.Edited by larymoencurly - 11/29/14 at 2:55am