I strongly recommend that you replace your original SPI flash memory with a brand new one, don't solder it back to the backplane, it will fail soon since SPI flash memories have limited lifetime (manufacture rated for just 100.000 erase/write cycles) when used as NVRAM for a Mac Pro. Start reading here, read all my posts on the subject from there. A cheap SPI flash programmer like ch341a will work for read/write the BootROM after the SPI flash memory is desoldered from the backplane. It's not possible to read or write to the SPI flash memory while it's soldered on the MP5,1 backplane. Desolder, reprogram and solder back the SPI flash, chip U8700 on the backplane.A replacement backplane is usually cheaper and you have to flash a clean version of your own Mac Pro BootROM image to the MATT card. Buy a Mac Pro MATT card and use it as a replacement SPI flash, this is not recommended since all MATT cards are clones and won't work for iCloud/iMessage/FaceTime.Don't mix early-2009 backplanes with mid-2010/mid-2012 CPU trays, or vice-versa - either scenario is a SMC firmware version mismatch and all your fans will run at maximum RPM, full time and without any software control. If you have a mid-2010 or mid-2012 you can use either 2010 or 2012 backplanes. Remember that you need a 2009 backplane if you have an early-2009 Mac Pro. Buy a replacement backplane on eBay and replace the backplane yourself, cheapest option if you can't solder SMD.If your early-2009 to mid-2012 is now bricked, you have three options:

Lot's of corrections, booting improvements, works with W3xxx Xeons. This BootROM version was never released outside betas. Updated APFSJumpStart EFI module - W3xxx Xeon bricker. Native NVMe boot support, several minor updates and corrections (NVMe is not stable/several bugs found)

Spectre/Meltdown mitigated microcodes on the April 2 Microcode Update Guidance. Missing microcodes and bricks the Mac Pro if you boot UEFI installed Windows 10 Initial APFS support, microcodes vulnerable to Spectre and MeltdownĪPFS support, microcodes vulnerable to Spectre and Meltdown First public released Mac Pro 5,1 firmware update, BootPicker improvements, microcodes vulnerable to Spectre and Meltdownīeta APFS support, microcodes vulnerable to Spectre and Meltdown

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