Late 2015 27" Not powering on, Fan starts but blank screen

[Ian_E]

Very odd one with my Late 2015 27" Mac

Worked fine yesterday morning, attempted to turn it on last night and the screen didn't come on, I could hear the fans

I held the power button down and it powered off, then after a few seconds, it powered back up by it's self, it keeps doing this.

So I spun it around and removed all but one of the Ram sticks, I could also see 3 green LEDS on the logic board.

Still not powering on, no backlight on the screen.

I left it unplugged for 40 mins or so and tried it again just the same.

I then tried it again and it booted fine, so I reinstalled the RAM and again it didn't boot.

Left it unplugged overnight and again it's not botted this morning.

I recently (July) replaced the Insternal Blade drive with a samsung 980 1TB drive with an adaptor and the CPU with an i7 and maxed out the ram, the machine has been working fine since.


Any ideas ?

Any Ideas ?

 

[Chuckeee]

Possible power supply failure?

 

[Ian_E]

Turned out to be a bad stick of memory, I put a single original 4gb Apple stick in and it booted, I then started to replace the 8gb stick till it stopped booting.