Strange boot behaviour (El Cap on Mac Pro 2008)

[Horsa]

Hi all,
I wasn't sure whether to post this in the desktop hardware section or as an OS-related query (because I don't know where the root of the problem lies), but here goes.

This morning I switched on my Early 2008 Mac Pro (running El Cap off an SSD - see hardware spec in my side panel) and something odd happened during the boot process.

The usual pale grey screen appeared, with the Apple logo and the dark grey progress bar under it. Normally, what happens next is that when the progress bar gets to a certain point the screen disappears and comes back again, the progress bar completes and the pale grey screen gives way to a dark grey one, in the middle of which I see the OSX login box.

This morning, when the pale grey screen disappeared, it re-appeared as pale grey and was just empty - no login box visible. My mouse pointer was visible on the screen and movable, and when I hit the "Open CD tray" button on the keyboard, it worked - so it was clear that the mouse and keyboard were working normally and interacting with the machine.

I then found out that when I hovered my mouse over the central portion of the blank screen, there was a small area where the pointer turned into a typing cursor. I sussed that this was where the password entry field should be, so I typed in my password and hit return. Result: a normal login (thank goodness).

I ran Onyx to check the startup disk and repair permissions etc., and it didn't find anything amiss.

Did a re-start and it booted normally - the dark grey screen appeared and the login box was visible.

I felt that the air coming out of the back of the case was a bit warm for a machine that was just idling, so I disconnected everything, took it away to a clean space and gave it a thorough dust-removal (as thorough as one can be without actually removing the CPU heatsinks). Very little dust came out, but I'm glad I made sure.

When I re-connected it and re-booted, I did a PRAM re-set for good measure. The machine booted normally. So, all in all - and unless the problem recurs - something of a mystery. ?

All and any thoughts gratefully received.

 

[chscag]

Not much you can do if it's working normally.

Probably some evil Gremlins were messing with you to see how you would react.

You passed the test. Seriously, probably a one time glitch that you shouldn't be concerned with unless it starts to happen again.

 

[pigoo3]

As mentioned...maybe a one-time glitch. As we use our computers day after day after day...lots of files are in use...and sometimes they get "confused" & need to be "repaired (which sometimes is done automatically by the macOS itself). Or sometimes doing things like rebooting, resetting the NVRAM, doing an SMC reset, running Onyx, etc...can help.

Sounds like one of these worked for you.

- Nick

 

[MarkAllread]

Just in case it happens again, put a piece of transparent sticky tape with the password dialog box on your screen in the right place so you don't have to go searching for it.
Sorry, couldn't resist!

 

[Horsa]

Thanks for your replies, guys. Unfortunately, today the problem repeated itself but worse. At switch-on, I got the startup chime, then a pale grey screen, but no mouse pointer or keyboard interaction possible. Then the dreaded flashing grey folder with a question mark appeared. For some reason I can't fathom, the machine couldn't find the OS from which to boot.

I shut down, unplugged the mains power and all unnecessary peripherals, reconnected the power and hit the startup button ...and it booted normally. I opened disk utility and did a live mode first aid check of the SSD system drive: no problems detected.

I can't believe the SSD system drive itself is failing - it's a Crucial BX500 and it was installed brand new just a year ago! However, because it is mounted on a PCIe card (OWC Mercury Accelsior S in slot 2) to ensure the best data transfer rates, the machine inevitably sees it as an "External Physical Volume". I do wonder whether the problem might lie with the PCIe card... but who can say?

 

[pigoo3]

If you think the issue could be the SSD or the PCIe card:

* If the SSD is the regular 2.5" drive form factor...remove it from the PCIe card...and install it directly into one of the Mac Pro's hard drive bays. Remove the PCIe card as well in case it's causing issues. If everything works fine after doing this...then the issue is probably the PCIe card. If the issue persists after removing the PCIe card & inserting the SSD into a regular HD bay...then try idea #2.

* 2nd idea. If you have a 2nd known good drive available to you (SSD or HD)...install the macOS on it (if not already installed)...and boot from it. This will definitely tell you if the current drive or PCIe card has issues...or if the issue is something else.

Please let us know how things go.

- Nick

 

[MarkAllread]

Nick beat me to it.
I'll add one thing.
Once you fix this, if you HAVEN'T got a bootable spinner in one of your slots, highly recommended you put one. It could be a clone of your SSD or something else. Best trouble-shooting tool is another bootable drive.
My 3 Mac Pros have all got multiple boot drives (I play around with stuff a lot ;-)

 

[pigoo3]

Best trouble-shooting tool is another bootable drive.

Most definitely!!!

- Nick

 

[Horsa]

Thought I'd hit you with an update on this situation.

The "Plain grey screen with no login field for the password" problem became more frequent, to the point that I was loathe to shut down my machine for fear I might never be allowed back into the OS. For days on end, the most I ever did was put it into sleep mode, from which it tended to wake up and let me log back in pretty reliably.

Then came the really weird turn. A few days ago, when waking the machine from sleep, I typed in my password, but the OS said no - and kept on saying no, repeatedly telling me that I had put in the wrong password. Uh???

I did a forced shutdown, rebooted in recovery mode and ran Disk Utility/first aid on the system drive - found nothing wrong. Booted back into the OS and it recognized my password. Phew! That was It for me, though: I was more convinced than ever that all of this nonsense was down to having my SSD System drive connected via a PCIe controller card.

I bought one of those nifty plastic HDD sled adapter frame things and mounted the SSD directly into bay 1. Result: boot takes a very few seconds longer, but after that, everything works pretty much as quickly as it did before, and - best of all - I have had no further impartial/flaky boot issues. Kinda stands to reason, really, doesn't it: the less "interpretive gubbins" between the drive and the logic board, the better the odds of reliability.

As to whether the OWC PCIe card is actually faulty, I can't say. I won't be using it again, though. I've got two free drive bays inside this machine. Whatever further drives I may fit, whether they be spinners or SSD, I'll be plugging them directly into the SATA sockets!

 

[Horsa]

Another update...

In the above post I mentioned that with the SSD System Drive plugged directly into bay 1, as expected the boot process took a few seconds longer than when it was mounted on the PCIe card. For the record, it was 47 seconds in the bay compared with 36 on the PCIe card.

Get this... It now takes LESS time to boot than when it was on the PCIe card! Don't ask me how - I've no idea and I haven't changed anything on the machine or its software - but from a cold start to seeing the login screen now takes 28 seconds. Go figure...

 

[daBee]

I'm the midst of coming off one of these, transitioning to a Mac Mini M1. Very interesting and frustrating.

Various software patches over the years are simply additions that need to be compiled before getting into your OS. My 2011 MacBook Air has the same thing.

Zap the PRAM before you start disconnecting things. My Pro has/had lots of things as peripherals. Much easier to zap the PRAM and reset things that needed to be redone, than messing with USB and FireWire and all that kak.

As an FYI, look for a Mac Mini M1 as a replacement. It's tiny, but the peripherals take on what the 4 or 5 drive bays did, and external docks can handle a lot of the work.

 

[daBee]

If you think the issue could be the SSD or the PCIe card:
- Nick

Monitoring log reports, the DVD bay was a culprit in two similar machines.