Installing Neogamma r8 isn't likely to full black screen brick a Wii. It must be something else at play.
A couple of things to try..
Hold reset and power on the Wii. Do you get Priiloader?
Remove any DVD, press power and watch the DVD slot for a quick dual flash from blue LED. Yes or No?
Can the Wii remote bring the Wii out of Red light standby by pressing the Wii remote power button. Yes or No?
And failing to follow the whole of a guide is EPIC FAIL. Only those knoweldgeable have the luxury of choosing which parts to perform and which parts to leave out.