BOOT_DEVICE_LED is solid red - Asus Motherboard

[Tamayonnasie]

I installed white cable extensions.
Turned computer back on, dram and cpu led are flashing - no display output
Pressed the dram button, no change.
Re seated the ram, no change.
Reset cmos by taking battery out for about 30 minutes, no change.
Next morning tried booting up the pc again.
Now the boot device led is solid red, there are no other leds on
My boot device is crucial bx100 ssd.
I tried resetting cmos again, no change.
(yes i have tried different ports and cables)

Rest of the Computer Specs:

Asus z170-a motherboard
r9 290x
i5-6600k
corsair h100i aio
nzxt hale 90v2 850 watt psu

 

[Shaun o]

Check you have connected the eight pin 12v Eatx power block direct from the PSU to the board.
See the two silver heat sinks on the motherboard the eight pin block is between the two at the top right of the picture.
Black in color.

If you do not connect the eight pin you will get a blinking red light on the cpu, and the memory leds
And the boot device will be a solid red lit color, and you will not get a video output signal from your Pci-e based r9 290x card.

It relates to a power problem across the whole motherboard. due to the eight pin not being connected, or seated right
Picture link bellow of where the eight pin is on the motherboard.
https://www.google.co.uk/search?q=Asus+z170-a&tbm=isch&imgil=V1WBOZMsMTd1dM%253A%253B61dGEVRWHHXkZM%253Bhttp%25253A%25252F%25252Fwww.hardwareheaven.com%25252F2015%25252F08%25252Fasus-z170-a-review-i7-6700k-skylake%25252F&source=iu&pf=m&fir=V1WBOZMsMTd1dM%253A%252C61dGEVRWHHXkZM%252C_&usg=__lcIXQx5amXqRkMXH54v7IMSrkwg%3D&biw=1920&bih=961&ved=0ahUKEwizi83k0pnLAhVrG5oKHbXyD68QyjcIMg&ei=83rSVvPFE-u26AS15b_4Cg#imgrc=V1WBOZMsMTd1dM%3A

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=&url=http%3A%2F%2Fwww.hardwareheaven.com%2F2015%2F08%2Fasus-z170-a-review-i7-6700k-skylake%2F&psig=AFQjCNGTGr7poCtMAZrQ2clX5bXU4X0O9w&ust=1456721580996409

 

[Tamayonnasie]

Check you have connected the eight pin 12v Eatx power block direct from the PSU to the board.
See the two silver heat sinks on the motherboard the eight pin block is between the two at the top right of the picture.
Black in color.

If you do not connect the eight pin you will get a blinking red light on the cpu, and the memory leds
And the boot device will be a solid red lit color, and you will not get a video output signal from your Pci-e based r9 290x card.

It relates to a power problem across the whole motherboard. due to the eight pin not being connected, or seated right
Picture link bellow of where the eight pin is on the motherboard.
https://www.google.co.uk/search?q=Asus+z170-a&tbm=isch&imgil=V1WBOZMsMTd1dM%253A%253B61dGEVRWHHXkZM%253Bhttp%25253A%25252F%25252Fwww.hardwareheaven.com%25252F2015%25252F08%25252Fasus-z170-a-review-i7-6700k-skylake%25252F&source=iu&pf=m&fir=V1WBOZMsMTd1dM%253A%252C61dGEVRWHHXkZM%252C_&usg=__lcIXQx5amXqRkMXH54v7IMSrkwg%3D&biw=1920&bih=961&ved=0ahUKEwizi83k0pnLAhVrG5oKHbXyD68QyjcIMg&ei=83rSVvPFE-u26AS15b_4Cg#imgrc=V1WBOZMsMTd1dM%3A

https://www.google.co.uk/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=&url=http%3A%2F%2Fwww.hardwareheaven.com%2F2015%2F08%2Fasus-z170-a-review-i7-6700k-skylake%2F&psig=AFQjCNGTGr7poCtMAZrQ2clX5bXU4X0O9w&ust=1456721580996409

Sorry if I wasnt clear enough in my post, but the only the boot device led is the only led on

 

[SDrockstar]

Windows was talking with my BIOS and at some point added my printer... And then the BIOS decided that would be a great boot device... Intermittent at first then couldn't shut down right or boot past post (unless I waited nearly 30min. on post screen). Boot light stayed on solid. Tried everything related directly to this issue and accidentally pressed the wrong link and found the printer idea. I had already done everything inside the case but never thought to unplug the printer.... VOILÀ! boots up fast as new.
NOTE: anything that needs to be identified (especially HDs, memory card readers and printers) can significantly increase boot times. Once configured correctly i can boot with it connected again but it doubles my boot times from 20sec to 45sec to have just my printer and memory card reader attached (no cards in, no print tasks)