I recently acquired an N9 from ebay for $30, and spend another $30 on a replacement screen, the screws were stripped and had to be permanently removed with a flathead screwdriver.

The N9 does not boot, and the only two causes I can think of are:
1: The proximity sensor may not be in correctly (a bit loose).
2: I'm using a Nokia n900's USB cable to charge it, which makes a white LED pop up.
Any attempts in detecting the N9 for flashing have resulted in nothing, no other computers appear to be able to detect it, even with libUSB.

What can I do at this point to get the N9 into an operational state?
The internals appear perfectly fine, although I shudder to think what happened to damage the gorilla glass so heavily originally.

I read that this problem somtimes occures after a replacement and you have to open your N9, unplug the cable from your battery and reattch it... But I don't remember it 100% now but I am sure this is the solution...

Can somone else confirm or help out?!

Maybe 1 of the 2 connector cables from and to the main board not put in properly or the iron flat pins on the back of ur screen needs to be raised a fraction more, i had the same isiue, and solved it by reconnect cables and raised pins, be carefull not to force any action, goodluck.

i used this youtube link to replace mine http://www.youtube.com/watch?v=9dxsTGpGRhs

leave it charging overnight . Maybe the battery is dead .

You can try to give power sraight to battery about 4V one minute, after that with wall charger rest. My n9 did not want to charge any other way, after battery get too empty.

Use a wall charger that outputs 2A. I replaced my battery and it worked straight with such a strong charger.