Diagnosing and understanding the symtoms of a HARD DRIVE FAILURE

[pawn3d]

timeline:

• im working on a friends imac g4 flatscreen.
• she told me it wouldn't start up at all, but when i pluged it in it worked fine.
• i thought she was crazy, but after using the machine for 5 hours it lost all power without warning.
• it refused to start up for 10 minutes of unpluging, disconecting mouse&keyboard, pluging it all back in and pressing the power button.

i want to say it's a hard drive failure, but i'm not certain.

1. are there any tests i can run or system logs i can check to verify that this is a hd failure?
2. what else could it be?

 

[ewilson6]

put in disk that came with computer and hold 'c' button down after restarting

see if HD comes up during install. If it comes up during install then try to archive and install OS.

If this works download SmartReporter from internet, this will tell you if your hard drive is failing.

Also power down iMac and remove back cover. There is a watch battery somewhere on the motherboard. Pop it out and replace it at Wal-Mart.


-Eric

 

[pawn3d]

put in disk that came with computer and hold 'c' button down after restarting

see if HD comes up during install. If it comes up during install then try to archive and install OS.

If this works download SmartReporter from internet, this will tell you if your hard drive is failing.

Also power down iMac and remove back cover. There is a watch battery somewhere on the motherboard. Pop it out and replace it at Wal-Mart.


-Eric

Thanks Eric. Helpful!
Do you know of a manual to get to the watch battery? Are there other tools I should know about that diagnose problems like motherboard or power supply failure?

 

[pawn3d]

other than a hard drive failure, are there any other known reasons an iMac would just shut down?

 

[VoodooDaddy]

Sounds like a heat issue related to the power supply. Im basing that on the same exact symptoms I had with an old windows box. It would shut down unexpectedly and couldnt be restarted for a few minutes. Replaced the power supply and problem was solved.

 

[mperkins37]

I would vote for Power transformer failure also, The fact that it started says the HD is probably not the problem. If the HD Died the screen would freeze.
Doubt it would power out the machine.

 

[Foxglove9]

I had an iMac G4 that had that same exact problem. I didn't know what it was it drove me nuts, I even did Disk Utility checks and it said everything was fine.

So I tested everything, and then finally after initializing the hard drive and reinstalling the OS that's when disk errors started popping up. I replaced the hard drive, and the problem never happened again.

So yeah despite Disk Utility saying the drive was fine, it was bad.

 

[ewilson6]

To remove cover, lay iMac carefully face down on a towel.

Remove 3-4 screws on back and remove cover.

Battery is in vuew small screwdriver will pop it out.

Takes 5 minutes or less to remove.

--Eric

 

[pawn3d]

Thanks, everyone. :0

2 votes for power supply failure
1 vote for hard drive
1 for watch battery.


I'm definitely going to replace the watch battery, as it's an easy one. Does anyone have anything else to add before I purchase a new transformer?

 

[pawn3d]

Eric, this is the battery, yes?
http://www.welovemacs.com/apim117flscb.html

 

[CanadaRAM]

The battery is NOT the cause of it suddenly powering off -- when the machine is on the battery has no function. It's only there to keep the PRAM alive when the machine is off.

Now it's still possible the battery needs replacing, but that would be incidental to the main problem. A dead battery typically shows up first as the machine reverting to a 1904 or 1969 date. Later, the machine would refuse to power on if the battery was completely dead.

I'm going to vote for power supply failure.

If it was the hard drive, it wouldn't have powered off. It may have frozen, or given the kernel panic screen, but not a complete powerdown.

 

[pawn3d]

The battery is NOT the cause of it suddenly powering off -- when the machine is on the battery has no function. It's only there to keep the PRAM alive when the machine is off.

Now it's still possible the battery needs replacing, but that would be incidental to the main problem. A dead battery typically shows up first as the machine reverting to a 1904 or 1969 date. Later, the machine would refuse to power on if the battery was completely dead.

I'm going to vote for power supply failure.

If it was the hard drive, it wouldn't have powered off. It may have frozen, or given the kernel panic screen, but not a complete powerdown.

and here i thought i could fix it for 6 bucks.

thanks for your answer. would you say a bad power supply could also be the reason the machine is stubborn to start up?

Just to clarify guys, i've been using this computer for about 7 hours and no crash. would a bad power supply stay on that long? is it possible a cable is loose?

 

[iPhil]

and here i thought i could fix it for 6 bucks.

thanks for your answer. would you say a bad power supply could also be the reason the machine is stubborn to start up?

Just to clarify guys, i've been using this computer for about 7 hours and no crash. would a bad power supply stay on that long? is it possible a cable is loose?

Check the power cable but it sounds like Power supply dying....



When you clicking or chirping on those lines then Hard drive is dying...

 

[nickf]

is it possible a cable is loose?

There may be a dry solder joint in there somewhere. I had a TV that would turn itself off after an hour or so. Basically thermal expansion would break the connection to a capacitor on the board. When it had cooled down a bit it turned itself back on. (Fixed it with a soldering iron when I'd had enough of it).

I'm not saying that this is occurring with your Mac, but it's a possibility.

 

[Foxglove9]

If it was the hard drive, it wouldn't have powered off. It may have frozen, or given the kernel panic screen, but not a complete powerdown.

Not true. My macbook just this week was just powering off by itself on startup. Because of my experience with the iMac I booted with the Leopard install disc and found out there was a major error with the hard drive. After repairs it works fine.

OP: If you do take apart that iMac make sure you have some thermal paste ready because you will want to reapply it according to Apple's repair document.

 

[pawn3d]

Not true. My macbook just this week was just powering off by itself on startup. Because of my experience with the iMac I booted with the Leopard install disc and found out there was a major error with the hard drive. After repairs it works fine.

OP: If you do take apart that iMac make sure you have some thermal paste ready because you will want to reapply it according to Apple's repair document.

dude, i found this awsome take apart!
http://www.mrtotes.co.uk/mrtotes/iMac Flat Panel.html

the pictures are crystal clear.

 

[ewilson6]

Yes those are the correct batteries , and after checking Wal-Mart does not carry them anymore....Sorry


--Eric

 

[CanadaRAM]

Not true. My macbook just this week was just powering off by itself on startup. Because of my experience with the iMac I booted with the Leopard install disc and found out there was a major error with the hard drive. After repairs it works fine.

Failing on startup is one thing, because the hard drive has to boot the OS, but powering down suddenly while in the middle of using the machine doesn't sound like hard drive failure to me. Whereas it is right on target for heat-induced power supply or voltage regulator failure.