transferring file to backup HD & power went out, now HD won't mount

[mamlukman]

I've not been able to find this problem anywhere, so maybe someone here can help.

I have a backup HD (80 Gb) on a G4 (c. 2002). It's an internal drive, and has been there since I bought the computer. It works fine. It's NOT the startup drive.

But as I was transferring a file from my main computer to this backup HD, the power went out, and of course both computers shut off. I restarted both computers, but now the G4 won't mount or recognize the internal backup HD. I tried disk utility, and it doesn't see it. I restarted the G4 a couple times, but that doesn't help.

Is there any way to get it to mount? Or should I just write it off?

Keep in mind there was nothing wrong with the HD. The problem seemed to be that the power went off in the middle of a file transfer.

 

[Amethyst1]

Does the drive spin up?

 

[1042686]

Bad cable? Fried port? Damaged psu cable?

I’d stick it in another box or usb/fw enclosure to see if it’ll show up. At that point you’d know somethings up with the g4 & not the drive. Conversely if it’s bad behavior persists in the new box, you know the drives failed.

 

[mamlukman]

Does the drive spin up?

who knows? It's internal, and the G4 makes a lot of noise.
[doublepost=1553195467][/doublepost]

Bad cable? Fried port? Damaged psu cable?

I’d stick it in another box or usb/fw enclosure to see if it’ll show up. At that point you’d know somethings up with the g4 & not the drive. Conversely if it’s bad behavior persists in the new box, you know the drives failed.

But the G4 works well otherwise--including mounting several internal and external HDs. And the odds that this HD would fail at the precise moment of a power failure are about 1 trillion to 1. To me it's clear that somehow the incomplete file that it was transferring is preventing it from showing up. There should be an obvious and easy fix, I just have no idea what that would be.

 

[Amethyst1]

You could put your hand on top of the hard drive to check if you can feel the vibration caused by the motor.

 

[eyoungren]

See if you can get a copy of Disk Warrior. More than likely the drive directory was damaged. DW can repair that, allowing the drive to mount.

 

[dwig]

See if you can get a copy of Disk Warrior. More than likely the drive directory was damaged. DW can repair that, allowing the drive to mount.

+1, and...

... get two UPS units, one for each computer, to prevent this type of issue in the future.

 

[1042686]

when the flow of electricity is interrupted it is sometimes followed by a surge that can damage
Componentry.

I hope DW is your fix. Best of luck to you.

 

[dwig]

when the flow of electricity is interrupted it is sometimes followed by a surge that can damage Componentry.
...

True, surges often occur as the result of whatever triggers the outage. This is why you should always use a UPS, which will provide not only battery power but also surge protection, with any computer or accessory device. The only exception would be when powering or charging a tablet, phone, or notebook that has its own battery and then you should use a surge protector.

 

[Traace]

First: Check if the motor is still running.

If it doesn't:
Many HDD PCBs contain a TVS diode in order to protect the circuit behind it. If can getting shorted due a voltage spike, Thus disable the whole HDD. Read more, here: https://community.wd.com/t/hdd-tvs-diode-faq/14692

But a PSU should detect a over-current produced by a shorted TVS diode and therefore shutdown.
Your PSU is still running, which leads to the conclusion that another protection component on the PCB must got broken. These other protection components often lead to a open circuit somewhere.So in this case you could check for some open fuses or zero-ohm resistors.

 

[mamlukman]

As part of the hardware explanation, I should add I am 71. "PCB," "TVS diode," "zero-ohm resistors," "PSU," etc. don't mean a heck of a lot to me. Also the computer in question is in an extremely awkward place. Could I get to it if my life were at stake? Sure. To rescue a hard drive? ......? So please think of me as your grandfather who has difficulty bending down to pick up a penny as you give advice!

I do have some other additional information: I was able to touch what I think is the drive in question, and it is warm and vibrates slightly. Today Disk Utility "sees" it, but won't allow me to do anything to it except erase it. I have Disk Warrior, and it "sees" it only if you click the "hardware" tab--otherwise, it doesn't appear on the list of drives for any other tabs. And the only thing I can do under the hardware tab is do an hourly check of the hardware status of all drives. I did this, and it appears that there is no hardware malfunction (it said it would post an alert if it found one, and there is no alert.)

If you click on "information" in Disk Utility, it gives "disk identifier" as "disk0" rather than a name like "disk3s2." Also it doesn't list "used space," "file count," etc. as it does with other disks. I'm guessing part (all?) of the problem could be solved if I could somehow "name" the HD. But I have no idea how.

So, my personal theory is my original one: the HD itself is OK. But the software somehow got screwed up as the power went out when a file was being copied to it. Maybe it's trying to complete the task, and that's it's priority rather than mounting? In any case, keep it mind this was a backup HD, so, although I'd rather not just erase it, that's a feasible alternative.

In view of all this, do you think I just just hit "erase" and hope that solves the problem with the drive?

 

[mamlukman]

OK, I tried erasing with Disk Utility, but it didn't work--it gave some message about "this HD is not compatible with the system selected." So although Disk Utility sees the drive, and the "erase" command is active (the only command that is), it won't erase it.

 

[1042686]

Pop is 75, so I've had my fair share of tech support keeping him & mom's macs, phones n peripherals synced & up to date over the years.

Anyhow, in all of my macs from Tiger to El Cap, the operating system hard drive's disk identifier/BSD node is Disk0. Are you sure that you have the correct hard drive? My laymen understanding is that drives are assigned via first come first serve so starting with the boot drive. Not much help I guess but I couldn't help but notice that.

I know you don't want to pull the powermac out, but if you're unable to fix via DU/DW software, remove the suspect drive (should be the middle drive on the ide pata cable - the end is your boot drive) and use another computer to investigate or attempt to erase. Windows Disk management (Control Panel ->Computer management) for example (that is if you have a bootcamp win install or box) has been a useful tool to me at times when dealing with pain in the arse drives - and then sometimes not. Sometimes the drive is just dead. Drives definitely wear out & fail over time and this one is 10+ years old (IIRC you stated this is the powermac's original hard drive configuration?).

For the sake of your own time and headache, considering its age & inconsistent behavior in DU & DW, you might consider replacing the wonky drive with a new pata drive or if getting into it really is tough, ask a wiley grandchild to help or you could pick up an external. Big, fresh external storage is cheap nowadays, so that's a plus. Just plug it in, point time machine at it (in system preferences) and let TM rip. USB1.1 speeds will be fine for your machine backups.

Either way best of luck to you.

 

[mamlukman]

Pop is 75, so I've had my fair share of tech support keeping him & mom's macs, phones n peripherals synced & up to date over the years.

Anyhow, in all of my macs from Tiger to El Cap, the operating system hard drive's disk identifier/BSD node is Disk0. Are you sure that you have the correct hard drive? My laymen understanding is that drives are assigned via first come first serve so starting with the boot drive. Not much help I guess but I couldn't help but notice that.

I know you don't want to pull the powermac out, but if you're unable to fix via DU/DW software, remove the suspect drive (should be the middle drive on the ide pata cable - the end is your boot drive) and use another computer to investigate or attempt to erase. Windows Disk management (Control Panel ->Computer management) for example (that is if you have a bootcamp win install or box) has been a useful tool to me at times when dealing with pain in the arse drives - and then sometimes not. Sometimes the drive is just dead. Drives definitely wear out & fail over time and this one is 10+ years old (IIRC you stated this is the powermac's original hard drive configuration?).

For the sake of your own time and headache, considering its age & inconsistent behavior in DU & DW, you might consider replacing the wonky drive with a new pata drive or if getting into it really is tough, ask a wiley grandchild to help or you could pick up an external. Big, fresh external storage is cheap nowadays, so that's a plus. Just plug it in, point time machine at it (in system preferences) and let TM rip. USB1.1 speeds will be fine for your machine backups.

Either way best of luck to you.

Thanks for your help! From my investigations, the "disk0" issue is relatively common--but as far as I can see, no one has a solution! [Of course this is the problem with the Internet--the solution might be there, but hidden among 10,000 messages.] It's definitely NOT the boot disk, since that one has a distinctive name and appears separately on the Disk Utility list. In any case, as I said, this was a backup HD, so I haven't lost anything. It's just annoying that the HD itself seems to be fine, but it's unusable because I can't re-format it. And I do have other external HDs I can use. And yes, at some point I'm sure I'll have to unplug everything and dig the computer out--last year I had to replace the power supply. It took me two days, but it worked the first time, and it was my technological feat of the year!