My Mac keeps shutting down

[Willie1925]

My Mac keeps shutting down it makes a kind of twang noise and immediately shuts down. I turn the power off, wait awhile and turn it back. My mac works for a while then decides to shut down again. Can anyone help me, how do I fix this problem
Thanks

 

[Cory Cooper]

Hello and welcome.

-Which exact model Mac?
-Which version of OS X/macOS?

It sounds like it may be a thermal issue, if it works for a little while then powers off.

C

 

[Willie1925]

I have a late 2012 iMac i7 27inch and recently updated to Catalina V10.15.2 but this started about 2 weeks before updated system. I have done a nit of research and perhaps the power system needs to be replaced. see this please

. Thanks for your help so far

 

[Willie1925]

 

[Willie1925]

 

[Cory Cooper]

Hello,

Yes, it could be that exact issue. Unfortunately, the Late 2012 iMacs are now Vintage, which means they cannot be repaired by Apple. Some third-party Apple Authorized Service Providers may be able to get the parts, but it could be very difficult. You may be able to source the power supply yourself, however the repair itself is very complex due to the adhesive strips that hold the LCD in place. In addition, other internal components could also be at fault, and can easily be damaged when repairing yourself without proper training.

I don't recommend you attempt the repair yourself...I would check with local Apple repair shops and get a quote.

Sorry I don't have better news...let us know how it goes.

C

 

[Willie1925]

Hi Cory, Thanks for your help. For the last 3 days it hasn't shut down. I followed the instruction to shut it down remove all power supply wait 30 seconds and then restart it so far so good. I think in the I may have to just bite the bullet and buy a new one. Regards Willie

 

[Cory Cooper]

No worries.

Excellent that the SMC reset seems to have worked for now. Keep us updated.

Good luck!

C

 

[Harry Trent]

Something like that could also be caused by overheating if the internal cooling fan was seized up or if dust has clogged the radiator. But an iMac is very difficult to work on because of the adhesive strips that secure the chassis to the display as Cory said. Supposedly, you can use a heat gun and guitar pick wedges to separate the two. I have only tried this on a macbook pro and without success.