On Sun, Sep 27, 2020 at 3:42 PM Angel Pons <th3fanbus@gmail.com> wrote:

Hi Clay,

On Sun, Sep 27, 2020 at 8:23 PM Clay Daniels <clay.daniels.jr@gmail.com> wrote:
>
> Looking for schematic for:
> MSI X570-A PRO (MS-7C37)
>
> Ivan Ivanov pointed out a very nice detailed view which I could not find in MSI marketing propaganda, and it looks like I will need to use a CH341A external programmer. This means I need to know if the vcc to the chip is 3.3v or 5v. I have no real clues without a schematic. Are these available?

VCC for SPI flash chips is never 5V. It's usually either 3.3V or 1.8V,
and the best way to know is to look at the chip itself. It's a WSON8
package located between the first PCIe x16 slot and the CPU heatsink
mount bracket, next to a connector labelled JSPI1. This connector is
NOT meant for in-system programming, but for plugging in another flash
chip and disabling the onboard one.

I think the chip in the picture is a Winbond. `W25Q*V*` chips run on
3.3V, whereas `W25Q*W*` chips are 1.8V parts. Note the `V` vs `W`
difference.

Angel, thanks for straightening me out. Yes, the little 8 pin chip just left of the JSPI1 header is definitely the flash rom chip. I can see it in the pictures and through the clear plastic side of the computer. What I need to do is open the cover up, get my glasses out, and read the chip top label on the chip. Even if I had a schematic it might not include the actual Winbond part number.

And I had wondered what use I could make of JSPI1. Not for flashing the bios chip, I see.

The MSI motherboard also has this rear-facing combination usb port & "flash button". Best I see from u-tube is that it is intended to flash your motherboard before it's installed. You can hook up a couple of power supply connectors, insert your usb with their bios file renamed to MSI.ROM, press the flash button, and it flashes the bios. Not guaranteed to work after the motherboard is fully hooked up, though. Odd.

Thanks for your help,

Clay