I successfully flashed my Bios on a MSI Z77A-G45 via the SPI1 header with a self-made rayer_spi cable. Now I tried to to fix the broken bios of a MSI Z77A-G43 Mainboard, which also uses a Winbond W25Q64FV chip. The Problem is that the programmer recognises the chip, but I am not able to program it correctly. If I verify the content it throws thousands of errors and I found out, that the supply voltage goes down to 1.9 V even with a powerfull source. But if I power on the Mainboard with its PSU, Vss of the bios chip has 3.3 V.
Now what I am wondering if I can do In-System Programming by powering up the mainboard and only use the data pins of the spi header. Problem is I don't know if this is possible, because CS# and DO are also on high level! And what do I do with the clk signal? Is it povided by the mainboard and messes up with the signal of the programmer? Or is it possible that the chip is electrically damaged, although I can read out its ID? Soldering it out is what I want to do last!