Replaced digitizer on my AT&T 16GB iPhone 4. Now, on boot, it shows the apple logo for around 11 seconds, and then crashes. It loops this until it runs out of battery. This occurs on ac power or battery. Oddly enough, if I remove the battery and try to power it with the ac charger, it acts the same, but crashes after only 4 or 5 seconds. Is this the end for my logic board or is there a better solution?

Thanks for your help.