Safe boot... Gray spinner not spinning...

[GeoFan49]

My MacBook Pro won't boot... What to try next?

Mac OS X 10.6.8 Snow Leopard, hard drive recovery...

Yesterday, due to an unrelated problem, had to do a hard shutdown. There was no apparent disk drive activity at the time of this shutdown, but there were more than a few open files and many active processes.

Before that shutdown, everything was normal for a few months, no changes...

The MBP had been booted normally from an EXTERNAL USB drive. The internal drive is a 1TB Yosemite boot drive with about 500 MB in use. The external USB drive is a 1TB Snow Leopard boot drive with about 900 MB in use. I use these two boot drives several times a week, rebooting as needed, when necessary. Gradually finding alternatives to each of the apps that were my favorites on Snow Leopard. Still NOT ready to ditch SL completely.

Immediately attempted to reboot normally from the external drive. Spinning wheel stopped after a few minutes, waited about 10 minutes, then did a hard reboot, once again, but this time in SAFE Mode.

Tried doing a SAFE MODE reboot, same thing happening again, gray spinner had stopped after a few minutes, then noticed flashing lights on the external drive case. So, I let it run overnight, attempting the SAFE boot. After 12 hours, still seeing flashing lites on external USB case now, BUT no spinning on the gray wheel of the startup screen.

I have a recent TimeMachine backup for both (internal and external) boot drives on separate partitions on yet another external USB, a 4TB drive.

Several Questions:

How long should I wait for SAFE Mode Reboot? How long should a full FSCK recovery take, for a 1TB 7200 RPM external boot drive with SL?

What is the chance that a hard-reboot can destroy an external USB drive!?

What to do next?

. . .

Background, details:

{{ My MBP MacBook Pro 64-Bit Core2Duo 2.53GHz MacBookPro5,4 Mid-2009 15" MC118LL/A Unibody aluminum. Upgraded RAM, Internal HDD, and new battery in late 2013. Currently has 8GB RAM, 1TB HD; Dual boot: Mac OS X 10.6.8 Snow Leopard, external USB drive; also OS X 10.10.5 Yosemite, internal 1TB hard drive. }}

Note: The internal drive was having many soft errors per day, about a year ago, so I replaced the internal drive cable (cost about $30) and the daily error rate improved about 90%. Still having a few soft errors per day, but not nearly as many as before changing that internal cable.

More: Both hard drives are 1TB, 7200RPM, SATA, HGST Travelstar, two years into three year warranties. External case is SIIG USB 3.0 to IDE/SATA enclosure.

 

[DeltaMac]

My MacBook Pro won't boot... What to try next?

Mac OS X 10.6.8 Snow Leopard, hard drive recovery...

Yesterday, due to an unrelated problem, had to do a hard shutdown. There was no apparent disk drive activity at the time of this shutdown, but there were more than a few open files and many active processes.

Before that shutdown, everything was normal for a few months, no changes...
...
Immediately attempted to reboot normally from the external drive. Spinning wheel stopped after a few minutes, waited about 10 minutes, then did a hard reboot, once again, but this time in SAFE Mode.

Tried doing a SAFE MODE reboot, same thing happening again, gray spinner had stopped after a few minutes, then noticed flashing lights on the external drive case. So, I let it run overnight, attempting the SAFE boot. After 12 hours, still seeing flashing lites on external USB case now, BUT no spinning on the gray wheel of the startup screen.
...
Several Questions:

How long should I wait for SAFE Mode Reboot? How long should a full FSCK recovery take, for a 1TB 7200 RPM external boot drive with SL?

What is the chance that a hard-reboot can destroy an external USB drive!?

What to do next?
. . .

I think that 30 minutes waiting for a boot to safe mode should be long enough for it to do something.
A forced-power off could easily give you problems with the drive's directory, and that could certainly result in booting problems.
So, what's next?
Boot to your Snow Leopard installer DVD. Run Disk Utility, and try a Repair Disk of your external Snow Leopard hard drive.
Run a repair twice. Once with the external device selected (the manufacturer's line for your Snow Leopard drive), then Repair again with the Snow Leopard partition selected. The repair process will be somewhat different on each. That MIGHT stop with an error that it can't fix. And, that would be the time that you reach for your copy of Disk Warrior. If you don't have Disk Warrior, this would be a good time to get it. (Disk Utility sometimes will report problems that are beyond its built-in capability.)

 

[GeoFan49]

Thank you DeltaMac for all the good ideas and suggestions.

Booting from my Yosemite 32GB SD card now!

Update: Gray screen with progress-bar proceeding...

. . . But now seems stopped dead at 1/3 of the way over...

Removed all external drives. Same result. No joy.

I have another external USB hard drive with SL, and yet another partition with Yosemite, but no DVD.

I guess I will need to remove the internal drive, that seems odd (to me.)

Can a newer OS X Disk Repair work to repair an earlier one?

 

[GeoFan49]

Followed suggestions from DeltaMac and booted from a Yosemite install SD card. Disk Utility ran overnight and then everything was again bootable. No data lost. Thanks, DeltaMac!

Having replaced the internal drive and internal cable (about a year ago) and still getting lots of I/O errors from the internal drive, I suspect the data path between the motherboard and the internal drive still has problems. Had to remove the internal drive and use a USB external drive case to make this MBP work again.