With the system powered down disconnect all drives(hdd, ssd and optical) and disconnect all external peripherals except for mouse, keyboard and monitor. Then turn it on and see if it stops in the same place or gives you an error along the lines of there not being any bootable devices installed.
If it does try and boot(get the boot error) then it's likely one of the devices you unplugged is causing the problem. Connect them back 1 at a time(shutting down in between of coarse as you don't want to hotswap anything) till you isolate which part it is.
If it stops in the same place, power down and remove the ram and then reinstall 1 stick into dimm slot 1(closest to the cpu) and try again. Test both sticks individually to see if one has failed.
Disconnected all drives and DVD reader and it came up saying
Current BIOS setting do not fully support the boot device.
Go to Advanced > Boot > CSM params and adjust ...
I couldn't find the CSM parameters.
I closed down, connected the SSD drive and switched on and I got the error again, the boot_device_LED.
So, what's wrong with the SSD drive, is it too full or is it something else. I purchased it 'used' on eBay at the time. Time to invest in a bigger and NEW drive?