Try a reset. Hold down the power button and the home button simultaneously until you see the apple logo. If this doesn't work, you likely blew a fuse. You can google the fuse locations and replace it or bridge it with a bit of solder. Good luck!
Buy it on ebay.com http://www.ebay.com/sch/i.html?_trksid=m...-810+digitizer&_sacat=0 Here's a link to a video showing the replacement of a similar device. If you haven't worked on these before consider taking it to a local repair shop and save yourself much grief... http://www.youtube.com/watch?v=F4Ly87OLC...
I had this problem and used electrician's tape to tape of the exposed metal around the bottom and it solved the problem. I theorized it was shorting when metal touched metal. But I've also read that magnets can cause this if they get to close to the digitizer so if you put the rare earth magnets back onto the glass' underside, make sure they are away from the digitizer itself. Good luck!
If the multimeter shows a reading on the pins that connect to the battery then you know you have current flowing through the board and making it to charge the battery. I check this to rule out fried board quickly. Also, an easy quick check is to look in all the USB ports and make sure none of them are damaged. if two pins in any of the USB ports are bent up and touching each other the computer will short and not start. Simply bending them so they no longer touch would resolve such an issue. Good luck!
Try putting a thin piece of plastic on top of the flex cable as you slide it in. This will provide more downward pressure. Although I have never used this technique for ipad I have successfully used this on PS3 drive flex cables and keyboard cables in laptops. The trick is to find a thin hard plastic and then cut it to the exact width of the flex cable. Good luck!
Looks like some of these presoldered digitizers are coming without the magnetic sensors which are located on the home button flex cable. After purchasing two of these I ended up having to harvest the OEM home button flex and moving it to the purchased digitizer. I sent a picture to the seller showing the issue. I figured I ought to put it up for your viewing as well. Note that this is showing one of the sensors near the home button. There is another sensor near the soldering joints which is a bit smaller. You can see how they work together in the youtube video above. Thanks, Mark T.
Its just to the left of the connector if holding the device with home button towards you. Under a scope you will be able to see it missing. If you don't have the resistor, you may want to just put a solder ball to bridgethe connection. DDon't quote me but I think a bridge of solder will work fine and not cause any problems.. That device went back with customer shortly after and unfortunately I never got photos. Good luck! - Mark
Here is an update in case someoneelse finds themselves with the same problem. I found a small resistor that had come off next to the battery push connector. Was able to resoler it and battery charged again. Barely visible without microscope.