iMac, possible PSU failure

[BOT Edward]

So, last year I purchased a second hand iMac for $80AUD, all it had wrong with it was a HDD failure (to which I replaced for nothing due to having a spare).

 

I think it's a 2009 model, its specs are listed below:

 

C2D @2.93ghz

4GB DDR3 

GT120

24" screen

 

Just 3 days ago I had it turned on in the morning, legally downloading some of my favorite video content, I left it to go make myself a coffee to which I returned to it being powered off.

Strange... I powered it back on only for it to not boot into OSX properly (stuck halfway on the grey progress bar) and turn off (i could hear the HDD discs spin down which indicated a total power cutoff).

I booted into the Recovery partition and ran a HDD check only for it to do the same thing.

 

I completely removed all power to it and left it for half an hour, I then plugged it all back in and tried booting into the Windows 7 partition (as it is a boot-camped machine), it booted up okay but after a minute it shut off again. 

I tried rebooting it, after the initial power-on sound it shut off again.

I've tried switching power cables and plugging it into a different wall socket to no avail.

 

Is there any way I can troubleshoot whether it's a mainboard fault or a PSU fault?

I assume it is a PSU failure as it just shuts off power completely at random times.

 

I dont want to order replacement parts and get the wrong thing as it can be rather costly, and if anyone has had any experience with replacing components inside a iMac you would know what a massive PITA it is.

 

Thanks Steve Jobs

 

 

[G33k 4 L1F3]

So, last year I purchased a second hand iMac for $80AUD, all it had wrong with it was a HDD failure (to which I replaced for nothing due to having a spare).

 

I think it's a 2009 model, its specs are listed below:

 

C2D @2.93ghz

4GB DDR3 

GT120

24" screen

 

Just 3 days ago I had it turned on in the morning, legally downloading some of my favorite video content, I left it to go make myself a coffee to which I returned to it being powered off.

Strange... I powered it back on only for it to not boot into OSX properly (stuck halfway on the grey progress bar) and turn off (i could hear the HDD discs spin down which indicated a total power cutoff).

I booted into the Recovery partition and ran a HDD check only for it to do the same thing.

 

I completely removed all power to it and left it for half an hour, I then plugged it all back in and tried booting into the Windows 7 partition (as it is a boot-camped machine), it booted up okay but after a minute it shut off again. 

I tried rebooting it, after the initial power-on sound it shut off again.

I've tried switching power cables and plugging it into a different wall socket to no avail.

 

Is there any way I can troubleshoot whether it's a mainboard fault or a PSU fault?

I assume it is a PSU failure as it just shuts off power completely at random times.

 

I dont want to order replacement parts and get the wrong thing as it can be rather costly, and if anyone has had any experience with replacing components inside a iMac you would know what a massive PITA it is.

Unless you have a PSU checker, or use the old paperclip bypass to see how long the PSU stays on until it turns off, It's all trial and error.

 

I found this with a 2010 model imac.. it was TL;DR, but you may find use for it. https://discussions.apple.com/thread/3867688

[BOT Edward]

Unless you have a PSU checker, or use the old paperclip bypass to see how long the PSU stays on until it turns off, It's all trial and error.

 

I found this with a 2010 model imac.. it was TL;DR, but you may find use for it. https://discussions.apple.com/thread/3867688

Those responses and posts seem to be that of a software issue.

I think this is more of a HDD issue due to the inability to even get past the pre-boot (i.e. before it can even be booted to a device at all, whether it be disk/network/hdd)

 

EDIT: thanks though

[G33k 4 L1F3]

Those responses and posts seem to be that of a software issue.

I think this is more of a HDD issue due to the inability to even get past the pre-boot (i.e. before it can even be booted to a device at all, whether it be disk/network/hdd)

 

EDIT: thanks though

Hey, Apple isn't my specialty (*unless Im eating it*), but Im glad I could shine a bit of light.

[BOT Edward]

Hey, Apple isn't my specialty (*unless Im eating it*), but Im glad I could shine a bit of light.

Yeah it's a shame more people *especially self-claimed IT geniuses* don't have knowledge in Apple support.

 

You really can't turn a blind eye to it especially since you will be generally supporting users who use Apple products.

That was one of the reasons i got the iMac (also cause it was cheap as chips), so I could gain more hands-on experience within OSX and with apple hardware in general to better support the users.

As learning proprietary stuff is a lot harder then learning more open source or generally known things like Android/windows

[linuxfan66]

Yeah it's a shame more people *especially self-claimed IT geniuses* don't have knowledge in Apple support.

 

You really can't turn a blind eye to it especially since you will be generally supporting users who use Apple products.

That was one of the reasons i got the iMac (also cause it was cheap as chips), so I could gain more hands-on experience within OSX and with apple hardware in general to better support the users.

As learning proprietary stuff is a lot harder then learning more open source or generally known things like Android/windows

Same...i bought my rackmount to actually own some realistic rackmount hardware...it took me ages to realize how the smartraid controller worked...

Also did you try booting linux from cd to see if it runs stably if you put that under load.

[zanthros]

Could it be overheating? did you clean it out of the dust bunnies inside? Are there any fans in it? are they running?Just a thought.

[simson0606]

you could try to run the apple hardware test, maybe it shines some light

[BOT Edward]

you could try to run the apple hardware test, maybe it shines some light

 

 

Could it be overheating? did you clean it out of the dust bunnies inside? Are there any fans in it? are they running?Just a thought.

 

 

Same...i bought my rackmount to actually own some realistic rackmount hardware...it took me ages to realize how the smartraid controller worked...

Also did you try booting linux from cd to see if it runs stably if you put that under load.

 

Thanks for the comments.

 

I havn't been able to run any tests on it due to working full time, it's difficult to find time to do anything.

 

Ill take another look at it tonight and run the hardware test and see what it picks up.

It is 6 years old (09 model) so I might need to replace the TIM on it and possibly replace fans if the bearings have gone out.

 

Currently using a travelmate b113M (i5 model) that I upgraded the RAM on from other laptops I have laying around and had to log in under cached credentials to get it back off an old secure domain of mine