Had a strange problem this morning when starting up my MP. The PCIe card is empty lying in slot 1, nothing attached.
I pressed power button, it chimed, showed the Apple, and then took several minutes to get to my desktop (I have an SSD installed. Normally, it takes 11s.)
Then, neither my cursor nor my USB keyboard worked, it showed as connected, but they didn't work.
So I had to hard reset the machine..
Waited 30s, pressed power button again. The Power-LED was on, I heard the fans of my GPU, but no chime. I opened the case, and a small LED and PCIe-card was on. So I turned the Mac off, removed the PCIe card, and tried again. It chimed, but again it took ages to get to my desktop, and still Mouse/keyboard not working.
Hard reset again, booted into the recovery partition, and fortunately everything worked fine there. I Repaired permissions on the system drive, restarted, and now everything is ok again.
First time my Mac was making real problems. Had some minor issues before, but it was always working.
Anyone experienced something similar?