MAcbook Pro 2013 A1502 no post

Hi
I have a Macbook pro A1502 that has been into a shop to have the screen replaced.
It has developed a problem since - it refuses to switch on just spins fan for a few secs then off.

The chap who owns it took it to have the screen replaced and when he got it back it worked then after a week or so this fault developed.

He took it back and they had it for over a month and were very unhelpful, he finally got it back off them in the same state. This is where he asked me to have a look.
I popped around to pick it up and it worked, booted up etc fine.
A few hours later he shut it down and it refuses to boot again, so I went back and collected.

I have found the following:

If I plug in the power cable it stays on, fans spin no boot and blank screen.
If I plug into HDMI it switches off dead.
If I disconnect the internal battery still same, fan keeps spinning no boot.

I read somewhere that if it switches on automatically when connecting the power then the keyboard is not detected, but the power button on the keyboard responds etc so I can't see this.

Any Mac gurus on here? Any suggestions!?

Cheers!

It sounds like the gpu is dying.is the motherboard the original one that came with mac.
Not a mac just guessing.

Sent from my LG-H815 using Tapatalk

Quite a few macbooks share that model number, 9 I think. The model number of the logic board is printed on the board near the cpu fan and you would need a microscope to see it and indeed to attempt any repair on this board. The number will look something like this 820-3476.
All power rails would need to be checked and there are many with PPBUS_G3H being a good place to start. Circuits and .brd files are available for most models.

Just because the power button lives near the keyboard doesn't mean it is a part of it, just a pretty good place for it to live.
I notice the engineer who replaced the screen is apparently being blamed for the power problem. The "fault" he induced was obviously on a slow burning fuse which took "a week or so " to develop.