Default tablet vibrates when turning on and backlight is on but blank screen

Hi can anyone tell me what steps I can take to restore my tablet. I have tried to obtain my serial with a500manager to follow some other threads advice but it doesn't do anything just locks up ..I can use adb commands but im at a loss on how to use them to try to get back my tablet ... if you guys can help me that would be awesome.. as im not familiar with getting serial numbers with adb and such ... haven't flashed many tablets just phones like galaxy series with odin etc.. so im in new territory but im eager to learn and not to naivete' ... thank you in advance for your help...