Hi there and welcome
Can you power off the Mac
then hold the SHIFT key and with it held, power on the Mac until you get to the sign in screen and then release it.
Tell me if you can then get to this please.
can you power it off.
Then remove all cables except the power cable.
Power it on and tell me please what then happens.
ok, then it is not this.
Power off the wifi router then try to start it please.
Tell me if it then starts (after enabling the router and getting internet again)
ok, I know you tried this already but repeat the procedure another 2 times please
After two times tell me if it then starts please
ok, can you attempt this please
Power off the mac
Then start the Mac and hold down the Command and R keys at startup.
Hold these keys until the Apple logo appears. After your computer finishes starting up, you should see a desktop with an OS X menu bar and an OS X Utilities window
choose Disk Utility from the Utilities window, or from the Installer menu if you're started from an installation disc.
Click the First Aid tab.
Click the disclosure triangle to the left of the hard drive icon to display the names of your hard disk volumes and partitions.
Select your Startup Disk (usually named "Macintosh HD").
Click Repair. Disk Utility checks and repairs the disk.
Let this complete and when it has, tell me if you still have the problem please.
Thanks, ***** ***** confirmed the issue
It is the motherboard that has faulted. As it goes blank it points to the onboard power supply or voltage regulator. A bad video card would still leave it running but with a blank screen
I am really sorry about this and you are going to have to return the Mac to have this replaced. It will be covered by the warranty if this has not expired, and the replacement will be done at no cost to you.
I am really sorry about this, and if you have problems, or would like any additional information or assistance, please do not hesitate to let me know.
And if you can take a second to rate my service by clicking one of the stars at the top of the page, then submit, that would be greatly appreciated.
Ok, I thought when you said it went off that it was powering off. In this event if it is still running it can be the video card (which is onboard) or the chipset when it tries to initialize the devices. But both are part of the motherboard and still requires this to be replaced.
If you would like any additional information or assistance, please do not hesitate to let me know.
Else if you can take a second to rate my service by clicking one of the stars at the top of the screen then submit, that would be greatly appreciated.
No, the motherboard is a board that holds all the components and the graphics and chipset along with the Bios, Sata ports are on this board.
Then rest of the components connect to it eg: Hard Disk
ok.. I wont ask about the rating again. We are only compensated when you do a positive rating, but I asked a few times and it appears this wont happen.
Fair enough, that's your choice of course. You have the information you need
All the best