Help! Saa b9-3 automatic year 2003
 

So, my car wouldn't start; called the tow guy and he tried to jump it; everything would work but the ignition. So, I had it towed to a mechanic and he hooked it up to a jumper for 2 days. Well, my ignition would turn on however, I now had no computer display or an instrument panel backlight. But all the instruments work; no computer display still. Does anybody have an idea what's wrong with my car? If I can fix it? Thank you!