[Midnite721]

ok so ive been reading the forums about, Nuked, Reinstall the OS, JL CMD, and nothing works... so it was working fine but my screen was cracked so what i ordered on ebay and just replaced it... its just blank and some time is get a red light if i leave it charging it yellow and so on but nothing on the screen.
now what im wondering is it the screen or is it the OS... when ever i try to wipe it nothing happens on JL CMD, when ever i try to re install the Os it gives me the error of application cannot find black berry... i did this one crackberry.com/blackberry-101-lecture-12-how-reload-operating-system-nuked-blackberry#comment-2544]BlackBerry 101: How to Reload the Operating System on a Nuked BlackBerry | CrackBerry.com
any tips or hints would be greatly appreciated.

PS: if you need any further info please let me know
----update-----
ok so i installed my old screen in and i cant really read what it says because its cracked... but i manage to make out "reload software 587"... i tried installing the OS and it doesnt connect to the BB again. also i saw my screen is 005/004 but i have no idea what the one i bought on ebay is its completely blank.