2013 MP Apple Diagnostics

[circuitt]

Question..
I've read the support file on Apple Diagnostics, basically Hold down D on restart.
What's odd is the screen just stays black and doesn't boot.
I tried to multiple times and nothing.. just black screen and I have to hard restart.
Any advice on this? not a big deal, it's a brand new Mac I got two weeks ago.
Just added some ram and wanted to test it.

 

[MarkJames68]

Works for me... but best way to test ram is to have a bootable USB or CD and run Memtest.

 

[circuitt]

maybe I'm doing it wrong, do I need a hard wired keyboard using a magic keyboard and holding down D on reboot.
like is said I hear the chime and screen just stays black. maybe I'm not holding it down long enough?

 

[MarkJames68]

I use a magic keyboard as well. Keep holding it down until the diagnostic screen comes up.

 

[circuitt]

Ahh found the problem, any startup key command that boots into OS X (safe mode,reset nvram,etc) will work. but if I try to boot into single user mode or diagnostics my monitors won't display anything. Tried HDMI into the same monitor and It was able to post. So using Mini display ports via thunderbolt connections my monitors don't recognize the video signal via some startup key commands but works with HDMI. I have a feeling it's my monitors (Dell p2415q 4k). they wake fine from sleep and work well but kinda annoying.