Chosen Solution
Hi everyone! I have a mid 2010 A1289 Mac Pro 5,1 It turns on. Front, rear, psu and gpu fans spin slowly, both optical drive and hdd spin on turn on, but there is no chime, no video and no power to keyboard, so resetting PRAM is not possible. If diag button pressed, PSU PWROK (Green), 5V STBY (Yellow), EFI DONE (Green), GPU OK (Green). I removed the backup battery to reset the Real Time Clock chip, and after doing this, the computers turns on automatically when plugged in ( as in power-on on ac back configuration). Tried apple’s suggested minimum configuration test. When turned on without processor, processor red light illuminates. And it goes off when processor is installed back. The dim leds never illuminate, whether dims are installed or not. Has anyone seen these symptoms before? Any help appreciated.
Turns out it was the CPU board. Bought another Mac Pro, same year/configuration, swapped the cpu trays and it worked. Swapped only ram and processor to the working tray and it worked. But when I tested the cpu board with the ram and processors that were working on the other machine, the issue returned. Hope this helps anyone in the same situation.
AH HA! First before anything else hold the Power button for 10-14 seconds, This may revive the Firmware.If that doesn’t The problem is the Main Board!Part: https://www.ebay.com/itm/115271299964?ha… Guide: @oldturkey03 Might be able to send you a guide.
