Cracked LCD, touch screen unresponsive, replacement necessary?

I dropped my phone, resulting in a very small crack in the LCD (not the glass cover) in the bottom right corner of my Galaxy S3. The touch screen is now unresponsive. Based on other similar questions, I fear I may need to replace the entire LCD/digitizer. Can find online for ~$85. Before I do this, is there any other way to test if the problem can be trouble-shooted by opening up the LCD backing (behind the mother board)? Could it be a connectivity issue with the digitizer cable and/or display cables? I tried disconnecting and re-connecting but didn't change status. Thank you!