MSI Z270-A Pro (MS-7A71 Ver 1.2) Schematic Request

[dicky96]

Hi guys
Does anyone have a schematic or board view for MS-7A71?

Thanks
Rich

[Rezistor]

Re: MSI Z270-A Pro (MS-7A71 Ver 1.2) Schematic Request

Hi guys
Does anyone have a schematic or board view for MS-7A71?

Thanks
Rich

MS-7A71 Rev 1.2 schematic and boardview

[re-atari]

Re: MSI Z270-A Pro (MS-7A71 Ver 1.2) Schematic Request

Hi guys
Does anyone have a schematic or board view for MS-7A71?

Thanks
Rich

Hi Richard,

I watched your YT video in which you tried to fix this mainboard (I've been a subscriber to your channel almost since the very start).

You could have saved yourself the trouble of desoldering the BIOS chip (twice), if you had used the JSPI1 socket to reprogram the BIOS chip. The sole purpose of this socket is (re)programming the BIOS, the pins are directly wired to the BIOS chip. It is more or less a more reliable version of a programming clip. I presume MSI uses this socket during production to program the BIOS. Detailed info about this socket is a bit hard to find, looks a bit like MSI views this as some sort of trade secret. So in that respect, it does makes sense you desoldered the BIOS chip in order to reprogram it.
About a programming clip: it can indeed be a bit unreliable. Although (in my experience) a lot of the horror stories using a clip are somewhat exaggerated. I have used both a 8-pin and a 16 pin clip numerous times successfully for reading and writing BIOS chips. Using a good quality clip and connecting it properly to the BIOS chip should give correct reads/writes.

Several years ago I fixed a MSI MS-7693 mainboard (ATI 970 chipset), that like your mainboard had a corrupt BIOS as well. I successfully reprogrammed it through the JSPI1 socket. The socket pins have 0.2mm spacing instead of the more common 0.254mm spacing. I used 2 wires with 5 leads each, to connect the JSPI1 socket to an 8-pin adapter that fits in a eprom programmer ZIF socket. I had the 2 wires in my surplus box, I think they were originally intended for connecting the audio out of a CD-Rom player to a mainboard or soundcard. Not sure, long time ago...
I did have to connect an ATX PSU to the mainboard, as the programmer could not deliver enough juice to supply power to all IC's on the mainboard. Using my TL866, I got an 'overload' error. With the ATX PSU connected, all IC's on the mainboard got enough power, and the error disappeared. IIRC I did not connect a wire between the VCC on the programmer ZIF socket and the JSPI1 socket. I cannot remember if I had to switch the PSU on, or if I could just leave it on standby.

I should have a description of the JSPI1 socket pin layout from back then stored on my laptop somewhere, but will have to search for it. I'm sure the schematics/boardview provided above will suffice to figure out how the socket and BIOS chip are wired up as well. The schematic should give you validation about the value of the missing resistor, which you mentioned in the update video about this mainboard's fix, as well.

As for the cause of a BIOS going corrupt on MSI mainboards, I suspect it has to do with the 'live update' feature their mainboards boast. This feature enables a BIOS update on a system that has fully started up Windows or what have you, and that is just asking for trouble/failures. IMHO a BIOS update should only be done on a system just running the BIOS setup.
So, in this case the saying 'it's not a bug, it's a feature' is not valid, rather quite the opposite, really.

re-atari

[andalusi]

Re: MSI Z270-A Pro (MS-7A71 Ver 1.2) Schematic Request

MS-7A71 Rev 1.2 schematic and boardview

Thank you. I Have a short circuit in ATX power on my board

[urribarrizr]

Muchas gracias Rezistor!
Thank you very much Rezistor!

in English please