Screen not working at all

My home button quit working on my iphone 3g a month ago. I had broken the glass on it, and relpaced it myself, when i turned it on the home button roughly worked, eventually stoped.

Well i decided i should go ahead and fix it, i ordered the 150.00 replacement lcd/screen for it so i could just plug it in and go. well, i plugged it in, turned it on, and my home button still didnt work. So i turned it off, opened it up, and it was still connected, nothing wrong. so i turned it back on, home button still didnt work. well i shut it off and put my old screen back in, naturally the home button still didnt work. So i put the new screen in it5 and turned it on, home button didnt work still, slid the slider, and the screen shut off. i pressed the lock button, nothing, slid my silence button, nothing, so i took that screen off, put the old one back on and pressed the lock button. nothing happens, press all the buttons, still nothing, so i thought maybe it was dead, so i put it on the charger, and it made the charging sound as if it was on, but still dark screen.

What now? im at a loss, both mentally and finacially 150 bucks.

If i cant get it working, i figure my best bet is buying a new one and ebaying the old one. right?