Mac Pro 5,1, 6 Core 3.46 GHz CPU, 32GB RAM, Radeon RX 570, 750 GB SSD, Mojave. Unit was working fine when shipped to buyer. He reported chime loop on startup. He tried another start up disk. Couldn't get beyond the chime loop. He shipped it back. It was, however a massive USPS shipping fail with heavily dinged box going both ways. Looked like they tossed it around. • I get it, open, make sure everything was seated properly. Looking clean and proper. No chime at all at startup. All fans working, Mac and graphics card. Pulled out all cards and memory, inspected and put back in. • Red LED light blinks on power up and power off. Diagnostic light on back panel: only the top LED lights up (green) when pushed. Still not sure which lights I should be seeing when the button is pressed. • Processor tray looked clean around CPU, removed cage and everything looked okay. Enough heat sink goop in place.. • Replaced PRAM battery just to make sure. • Memory seems fine, no red lights • Still nothing CPU or Graphics card fail? Don't have another card to test. All circuit boards clean and visually sound. If it's the CPU, that's an easy job to swap out. I put this one in a couple years ago (OWC) Any other places I should be looking? Would love to fix this myself. |