It is not display problem but symptom of corrupted internal nand, eMMc as dackota said. Bootloader is probably still available but Partitions Information Table is damaged and switched to read only mode. You will not be able to flash anything.  
 
You need to replace your motherboard or at least reflow new eMMc chip. Sorry it is so called hard brick or sudden death.  
 
You can check display by entering download mode. It is displayed correctly. Fuzzy screen while booting shows because bootloader can't read data to init system.  
 
You can try to flash only param.bin, same .pit file or anything else via Odin or Heimdall but it will end at Setup Connection and write fail errors. Sorry bro. 90 percent of nand flash chips in s3 are physically faulty. Samsung replaces those motherboard under warranty, but if it's void or outdated you need to pay for repair.  
In some countries it is too expensive and worthless. In Poland, where I live, it is cost of 50-70 bucks. New i9300 or i9305 you can have for circa about 200$.