My Mid 2012 Retina 15-inch A1398 MacBook Pro shuts down after 15 minutes of usage

Is this happening on wall power as well as battery? If battery only, the symptoms are classic for either a worn-out battery or a non-Apple battery.

If it happens on wall power, does the battery icon on the menu bar show that the computer is charging during the short times you can see the screen?

If you wiggle the power connector do you see momentary changes in the display?

If it is the battery I don't hold a lot of hope. Apple won't service 2012 models any more.

Worse, Apple glues batteries in place in Retina Macbook Pros. They cannot be removed without toxic and flammable solvents that cannot be stored or used in a retail space without violating a litany of OSHA and environmental regulations and fire codes. Therefore, most independent service providers won't change batteries, plus cannot get an original Apple battery any more.

Peter_Grigorian wrote:

My Mid 2012 Retina 15 inch A1298 MacBook Pro started behaving really weird recently - all of a sudden, it started malfunctioning after over 12 years of normal operation. When I try booting it off, I don't see anything on the screen, yet the Apple logo on the back glows up. Sometimes after several attempts the computer boots of and everything seems normal until it shuts down 15-20 minutes after booting off. 

Could someone tell me if what could be the source of the problem and the culprit. Is it more a software related issue or more of a hardware related issue? 

Thank got I could get the data out of the computer using some conversion technology so now I don't worry about the data, I just want to bring computer back to working condition. 

Thanks in advance!

Your Mac is 12 years old...

see vintage and obsolete:

Obtaining service for your Apple product after an expired warranty - Apple Support

Obtaining service for your Apple product after an expired ...

If you have an external bootclone as a backup try booting externally—this would be a good test if it is simply your SSD is failing(?)

boot clone How to create a boot clone - Apple Community

the basic trouble shooting—

Try resetting the System Management Controller Reset the SMC of your Mac - Apple Support

Try resetting NVRAM/PRAM Reset NVRAM on your Mac - Apple Support

(get at least two-three rounds of the chimes when holding the NVRAM Reset)