iMac won't turn on

Hello all. New to the forum. My iMac has been working flawlessly for years until Saturday when it stopped responding (screen froze up with lines going across). I turned it off and tried to turn it back on, but it would not start. It's an older version (24" early 08 model), but have no idea what could be wrong. I did a bunch of research and tried everything I can find on resetting things (like most of the stuff here http://www.macworld.co.uk/how-to/mac/steps-take-when-your-mac-wont-start-3423817 /). I don't think it's actually getting far enough in the boot cycle to do anything. I can hear things start up, but it goes a few seconds, and then shuts down and tries to start again. No lights come on the key board, and there are no beeps. To make things worse, I put in my Snow Leopard CD to try and boot into that and now I can't get it out (of course after a lot of research I realized that it may need to boot into the original OS disk). But I really don't think it's getting far enough to even try the CD. I did pull my memory 1 by 1 to see if that would change things, but it didn't help (I upgraded mem years ago, so I still need to dig out the old stuff to see if that helps). Any suggestions on what it may be or what I can try would be greatly appreciated.

Thanks. Paul.

Pablorock said:

I don't think it's actually getting far enough in the boot cycle to do anything. I can hear things start up, but it goes a few seconds, and then shuts down and tries to start again.

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Firstly this computer DOES turn on…per the details on the quote. Thus the thread title of "iMac won't turn on" is not correct. Small details like this are very very important when trying to diagnose & evaluate a situation.

If I'm understanding things correctly. This iMac does turn on…and what it's not doing is fully booting to the desktop as normal. If this is correct…then:

- Do you hear the "Happy Mac" startup sound when the computer is first turned on (Bonggg)?
- Does the iMac's display light up (illuminate)?
- If the display does light up…do you see anything on the display for the time that the display stays illuminated (any icon's, messages, etc.)?
- When you inserted your Snow Leopard DVD…did you press the "c" key immediately…which tell's the computer to boot from the CD? If not…give it a try.

Will attempt to proceed further when answers are received.

- Nick

Hi Paul and Welcome to the forum!

With the symptoms you have listed - frozen screen with lines, failure to boot - and the steps you have already taken, it sounds like it is dying. At this point I hope you have a good backup.

This is a 2008 which means it is 8 years old, as I am sure you know. If it were mine and having already tried all the steps you tried, I would be looking for a replacement computer. If you do not have a good backup I suggest pulling the hard drive, purchase a hard drive external drive adapter and attaching to another mac to get any data off of it - if the hard drive is working that is.

Lisa

pigoo3 said:

Firstly this computer DOES turn on…per the details on the quote. Thus the thread title of "iMac won't turn on" is not correct. Small details like this are very very important when trying to diagnose & evaluate a situation.

If I'm understanding things correctly. This iMac does turn on…and what it's not doing is fully booting to the desktop as normal. If this is correct…then:

- Do you hear the "Happy Mac" startup sound when the computer is first turned on (Bonggg)?
- Does the iMac's display light up (illuminate)?
- If the display does light up…do you see anything on the display for the time that the display stays illuminated (any icon's, messages, etc.)?
- When you inserted your Snow Leopard DVD…did you press the "c" key immediately…which tell's the computer to boot from the CD? If not…give it a try.

Will attempt to proceed further when answers are received.

- Nick

Click to expand...

Thanks for the quick reply. Sorry, maybe that is the wrong title (but it's close). No, I don't hear and bongs or anything (so the mac ain't happy). When I hit the power button, it starts to turn on (I can hear things spinning up), but nothing after that. Can't tell if its the hard drive or just the disk drive spinning up. The screen doesn't go grey but I can tell the back light comes on, but that's it. I have tried C key, but nothing happens. I goes for about 5 seconds, then shuts down and tries to start again (and will do that over and over).

And I am not all that concerned with the data. Everything important is backed up (except my garage band tracks). This isn't my primary machine. I most use it for fooling around with graphics and movies and playing with garage band.

Pablorock said:

No, I don't hear and bongs or anything (so the mac ain't happy).

Click to expand...

Just so we are 100% clear on this. Do you (or did you) normally hear the "Happy Mac" startup sound before this problem started?

Pablorock said:

When I hit the power button, it starts to turn on (I can hear things spinning up), but nothing after that. Can't tell if its the hard drive or just the disk drive spinning up.

Click to expand...

Since the Snow Leopard DVD is "stuck" in the optical drive…you may be hearing both drives (the optical drive & the hard drive spinning up).

Pablorock said:

The screen doesn't go grey but I can tell the back light comes on, but that's it.

Click to expand...

I think that we need to be very clear on this. Does the iMac's display illuminate or not?

Pablorock said:

I have tried C key, but nothing happens. I goes for about 5 seconds, then shuts down and tries to start again (and will do that over and over).

Click to expand...

Ok…thanks for the info & trying.

Pablorock said:

And I am not all that concerned with the data. Everything important is backed up (except my garage band tracks). This isn't my primary machine. I most use it for fooling around with graphics and movies and playing with garage band.

Click to expand...

Great that everything is backed up!

At this point (depending on the answers above)…my next thought would have been to try a different hard drive to see if the computer would boot/startup with it. But:

- Since you are not getting any icons or warnings on the display…it seems like the problem is somewhere else.
- Also…since the computer will not boot from the Snow Leopard disk…this kind of reinforces things that the problem lies somewhere else (assuming you are using a good/non-damaged retail Snow Leopard disk).

If I was to hazard a guess (since the computer seems to be in a "restart loop"...only starts up for a short bit…then repeats the process). It sounds like the problem is more serious…and could be a logic board issue.

Here is one more thing to try. Try booting up in "Safe Mode"…by holding down the "Shift" key on reboot:

https://support.apple.com/en-us/HT201262

- Nick

p.s. One more thing. What OS is installed on the hard drive? If it's 10.7 or later…you could also try booting into the Recovery Partition by pressing the command + r keys (two keys) on reboot.

Truthfully, I don't remember if I heard the chime, but I'm pretty sure I did (it's usually always on).

It depends on what you mean by illuminate. Does it actually display anything? No. There is no color or anything (not a single pixel gets lit). I can just tell the back light comes on (it goes from total black, to not total black).

As far as OS, I think I'm on El Capitan, but not sure. If it came up as an update in the app store, I definitely did, but if not, I may be on Yosemite I bought a copy of Snow Leopard to be able to upgrade to the latest versions. I use Parallels and the new versions required an update of the OS (I run Corel Draw a lot. I started learning AI, but I have been using Corel since it's existence, so it's a slow learning curve and I don't have a lot of time to play). And yes, my Snow Leopard is a valid good copy (the only time I ever touched it was to upgrade a year or two ago. Been in the original package since.

I tried the shift key, but nothing. I also tried ctrl-r (as well as a couple of other things like command-option-p-r). I don't think it's even getting far enough to accept input form the keyboard. Neither the cap or num key light up, nor does the mouse. I would think I would get some sort of light on the keyboard if it got to recognizing that. Correct? (I have tried switching usb ports, but nothing)

(As an FYI, I am fairly technical. I have fixed 100s of PCs in my days. From floppy drives to mother boards, if it's in a PC, I've changed it. This is just my first and only mac, so I have no idea what problems come up and what they look like. So don't be afraid to ask me to try things).

I really appreciate your help and any more suggestions or thoughts would be helpful.
Thanks. Paul.

(what makes this kind of funny, is that my friend called me last thursday because his iMac died. His I can tell was a hard drive failure. Said he heard a loud clicking sound, then it died).

Pablorock said:

Truthfully, I don't remember if I heard the chime, but I'm pretty sure I did (it's usually always on).

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I understand. Many of us "sleep" our computers when not in use…and don't reboot them very often to hear the startup sound.

Pablorock said:

It depends on what you mean by illuminate. Does it actually display anything? No. There is no color or anything (not a single pixel gets lit). I can just tell the back light comes on (it goes from total black, to not total black).

Click to expand...

I think that here is where your computer knowledge (mentioned below) is causing a bit a "roadblock" to communication (you're getting way to technical for this discussion). "Illuminate" simply means does the iMac's display light up (become brighter). Please don't "over-think" this.

Illuminate = light (normal brightness if the computer was functioning properly). Simple as that. "Displaying something" is a different matter.

Pablorock said:

As far as OS, I think I'm on El Capitan, but not sure. If it came up as an update in the app store, I definitely did, but if not, I may be on Yosemite I bought a copy of Snow Leopard to be able to upgrade to the latest versions.

Click to expand...

Good deal Was only asking to see if we could try the Recovery Partition troubleshooting step.

Pablorock said:

I tried the shift key, but nothing. I also tried ctrl-r (as well as a couple of other things like command-option-p-r).

Click to expand...

Ok…good deal again. Too bad nothing worked.

Pablorock said:

I don't think it's even getting far enough to accept input form the keyboard. Neither the cap or num key light up, nor does the mouse. I would think I would get some sort of light on the keyboard if it got to recognizing that. Correct? (I have tried switching usb ports, but nothing).

Click to expand...

Understandable if this "reboot cycle" is happening quickly.

Pablorock said:

(As an FYI, I am fairly technical. I have fixed 100s of PCs in my days. From floppy drives to mother boards, if it's in a PC, I've changed it. This is just my first and only mac, so I have no idea what problems come up and what they look like. So don't be afraid to ask me to try things).

Click to expand...

Great to know. I mostly assume (unless told otherwise) that I'm helping a novice…and I try to explain things in detail as much as possible. As well as not getting too technical.

- Nick

p.s. One more thing to try. Try an SMC Reset:

https://support.apple.com/en-us/HT201295

Fingers crossed!

I think I tried the SMC reset before, and just tried it again, and nothing. Still in that quick boot cycle.

Pablorock said:

I think I tried the SMC reset before, and just tried it again, and nothing. Still in that quick boot cycle.

Click to expand...

Ok…thanks for trying.

I wanted to say that although in the back of my mind I'm thinking that this computer may have serious issues. I trying to first exhaust all possible troubleshooting steps before declaring the computer a goner.

I know that this computer is having this quick boot cycle…and it sounds like the display is not lighting up (no illumination). But still…here's something else to try. If this computer is having a display problem (or illumination problem)…and with your computer experience…you know how if the computer is in a darkened room you can shine a flashlight at just the correct angle & see the desktop (if there's something there to see). Give this a try.

And/or…you could try connecting an external monitor to the iMac…and see if anything can be seen on the external display (illumination or something displayed of some sort).

Good luck,

- Nick

I don't have the cable to add a display, but I can see that there is nothing on the display. As I mentioned before (incorrectly I now know), it looks like the back light is on. But now I see that this is an active matrix display and not a back-lit led display (so there is no back light to come on). So it is getting power to the display, just not far enough in the boot to display anything. Could it be a bad video card? Or is it as bad as the mother board?

Pablorock said:

So it is getting power to the display, just not far enough in the boot to display anything. Could it be a bad video card? Or is it as bad as the mother board?

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If it were only a video problem…the computer would probably boot ok (wouldn't have the boot cycle problem). You just wouldn't be able to see anything or things might look distorted.

It would be nice to have an external display attached…just to confirm things.

This may sound silly…but is there any chance the power button is malfunctioning or stuck?

- Nick

I don't think it's a power button issue. It seems to start up and shut down on first press without issue. (but I'll play with it a bit). I mention video because that's what looked strange when it died. At first it just froze on me, then a bunch of lines on the screen. Hopefully it's not the video because it seems that's more expensive than a mother board.

Can you think of anything else to try?

Pablorock said:

Can you think of anything else to try?

Click to expand...

The rebooting problem is the big issue. Even if there was a video issue…the computer should boot. And even if the hard drive was bad…the iMac's display would illuminate & you would see a folder with a flashing "?" icon.

As far as replacing the video card. Depends on the exact iMac model. Many iMac's have soldered in video hardware…thus the video card is not replaceable. And like you mentioned. On iMac's where the video card is replaceable…replacements can be pretty expensive.

If you wanted to test the status of the internal HD. You could remove it…place it into an external HD case…and plug it into a 2nd computer.

By the way…to get the Snow Leopard DVD out of the optical drive…upon restart…press & hold down the mouse button. If things are working properly…this should eject the DVD.

I'm thinking things are looking like a hardware issue. Namely the logic board. Or maybe a bad or weak power supply.

- Nick

Thanks for all your help. I'm going to try and play with it a bit. I may try to take it apart to see if there is anything I can do from there. I'll try to see if I can read the drive from another machine. The mother boards don't seem to be that expensive ($89 w/processor shipped on e-bay), that may be worth a try. If I get anywhere, I will re-post with an update.

Again, thanks for the help and all your time.
Paul.

P.S. This seems to be a great forum. I posted the same question on the Apple forum yesterday, and the only response I got was "take it to the apple store". That's like telling everyone that visits the BMW forum I use to "take it to the dealer". Not sure why someone would think that the answer I was looking for to a broken 8 year computer would be take it in to get it fixed!

I'm thinking things are looking like a hardware issue. Namely the logic board. Or maybe a bad or weak power supply.

Click to expand...

Wow Nick... the doctor is in! Good exhaustive trouble shooting especially when you're not at the scene. By the way, I agree with your diagnosis.

Pablorock said:

I posted the same question on the Apple forum yesterday, and the only response I got was "take it to the apple store".

Click to expand...

This actually wasn't very good advice…but not for the obvious reason. Apple tends to categorize older Mac's as "vintage"…and doesn't work on them. A 2008 iMac probably falls into this category.

- Nick

Thanks Charlie. Was hoping the computer wasn't DOA…and one of the troubleshooting steps might "take hold".

- Nick