Mid 2011 21.5 inch iMac shuts off randomly and SMC reset doesn't fix it.

[Deathstroke]

So heres the skinny;

iMac was working fine no problems what so ever, watch movies, play games do, do them at the same time too. On Wednesday night, i notice the screen go black and I figured it just went to sleep so I left it alone.

The next day i found out it wasn't asleep, but off so I tried turning it on to no avail. Tried the SMC reset didn't work as it was supposed to.

I had to wait at least 10-15 min for the SMC reset to work, I had left the plug out for that time and only then did it work.

So it booted up and everything was running smoothly again, until it just shut off on me again. I re did the SMC process again and booted it up and shut it off and then tried powering it back on. Works.

Then again it shuts off when im using it.

Its not making any weird noises, and the fans seem to be running appropriately. Tested watching a movie for temperature rating and its at 42 C and I even turned the fans on highest via istatspro and it still zapped on me.

So clearly it may not be due to overheating, but a power supply? Thats what I think but im not too positive and im wondering if anyone else has had this problem and can guide me in the right direction.

I don't got apple care and I don't really wanna fork over an arm and a leg for the problem to come back. Help anyone
I also think its utter bs that a company like apple charges you to friggin ask them whats wrong with your computer. Extremely frustrating

EDIT:
I loaded up the Windows partition as well, and it zapped there too.
I can't run a hardware test because it doesn't stay on long enough for that to happen.

Update: So It seems that my iMac turns off whenever im watching a movie or playing a game, the temp reaches about 42 C and then shuts off even with the fans at max.

 

[rkaufmann87]

So heres the skinny;

iMac was working fine no problems what so ever, watch movies, play games do, do them at the same time too. On Wednesday night, i notice the screen go black and I figured it just went to sleep so I left it alone.

The next day i found out it wasn't asleep, but off so I tried turning it on to no avail. Tried the SMC reset didn't work as it was supposed to.

I had to wait at least 10-15 min for the SMC reset to work, I had left the plug out for that time and only then did it work.

So it booted up and everything was running smoothly again, until it just shut off on me again. I re did the SMC process again and booted it up and shut it off and then tried powering it back on. Works.

Then again it shuts off when im using it.

Its not making any weird noises, and the fans seem to be running appropriately. Tested watching a movie for temperature rating and its at 42 C and I even turned the fans on highest via istatspro and it still zapped on me.

So clearly it may not be due to overheating, but a power supply? Thats what I think but im not too positive and im wondering if anyone else has had this problem and can guide me in the right direction.

I don't got apple care and I don't really wanna fork over an arm and a leg for the problem to come back. Help anyone

You may have failing hardware. Run Apple's Hardware Test in Extended Mode 2-3 times back to back. The reason to run it multiple times is AHT does not always find errors after the 1st or second pass. However when it does they are correct. If it finds an error (remember run in EXTENDED MODE) then you will have to get it repaired. Apple does not publish the error codes, someone here may know what a code means however your best bet is to take it into an AASP for repair.

 

[Deathstroke]

You may have failing hardware. Run Apple's Hardware Test in Extended Mode 2-3 times back to back. The reason to run it multiple times is AHT does not always find errors after the 1st or second pass. However when it does they are correct. If it finds an error (remember run in EXTENDED MODE) then you will have to get it repaired. Apple does not publish the error codes, someone here may know what a code means however your best bet is to take it into an AASP for repair.

That would be lovely, but I have already tried to run the extended test and it shuts off during the test. I have only managed to get the regular test to run, my iMac won't stay on for an hour plus for me to test it unfortunately

 

[hfg]

Have you checked your temperatures using iStat or similar?

Perhaps the internal heatsink/fan is clogged and not cooling properly ... it will probably feel hot at the top vent unless there is no air at all. You could run one of the fan control programs and rev up the fan to the max to verify it does, in fact, run ... and to possibly blow out some of he dust.

 

[Deathstroke]

Have you checked your temperatures using iStat or similar?

Perhaps the internal heatsink/fan is clogged and not cooling properly ... it will probably feel hot at the top vent unless there is no air at all. You could run one of the fan control programs and rev up the fan to the max to verify it does, in fact, run ... and to possibly blow out some of he dust.

Just got home...Ill try this out before I go to bed.

Thanks for the suggestion

 

[Deathstroke]

Have you checked your temperatures using iStat or similar?

Perhaps the internal heatsink/fan is clogged and not cooling properly ... it will probably feel hot at the top vent unless there is no air at all. You could run one of the fan control programs and rev up the fan to the max to verify it does, in fact, run ... and to possibly blow out some of he dust.

Well the fan does run at max, and I honestly don't see any issue with it. Computer stays on fine now, until I try playing a game...then it heats up but it only 39 degrees celsius...where on idle its like at 34-36 degree Celsius, so Im really stuck on what the problem is, maybe the GPU is done?

 

[Deathstroke]

Update:

Computer randomly worked after i left it unplugged for a day. And it was working extremely well, like normal for the past week. Now it just turned off again

I have no idea whats going on