Boot to Blackscreen, No Fixes Working

Hello,

I have spent a while looking into this and none of the 'fixes' I have tried work.

Basically, when I power up the Mac I hear the boo sound, but the screen will stay black. I have reset the SMC and theNVRAM/PRAM. I have tried starting in safe mode and tried to reset the brightness. I have not done any resent updates nor do I have any external devices attached.

If I attach it to a monitor with a hdmi cable I can see the apple load screen on the monitor and the loading 'circle' but then it just goes to a bright white screen.

I'm out of ideas. Does any one have an idea of what this might be?